data storage controllers and data storage devices employing lossless or lossy data compression and decompression to provide accelerated data storage and retrieval bandwidth. In one embodiment of the invention, a composite disk controller provides data storage and retrieval acceleration using multiple caches for data pipelining and increased throughput. In another embodiment of the invention, the disk controller with acceleration is embedded in the storage device and utilized for data storage and retrieval acceleration.

Patent
   7376772
Priority
Feb 03 2000
Filed
Apr 08 2006
Issued
May 20 2008
Expiry
Feb 02 2021
Assg.orig
Entity
Large
95
293
EXPIRED
13. A system comprising:
a processor comprising a data compression engine for compressing data stored to a data storage device;
a programmable logic device, wherein the programmable logic device is programmed by the processor to instantiate a first interface for operatively interfacing the data storage controller to the data storage device and to instantiate a second interface for operatively interfacing the data storage controller to a host system;
a non-volatile memory device, for storing logic code associated with the processor, the first interface and the second interface; and
a cache memory device for temporarily storing data that is processed by or transmitted through the data storage controller; wherein the processor further comprises a bandwidth allocation controller for controlling access to the cache memory device by the data compression engine, the first interface and the second interface.
1. A system comprising:
a processor comprising a data compression engine for compressing data stored to a data storage device and for decompressing data retrieved from the data storage device;
a programmable logic device, wherein the programmable logic device is programmed by the processor to instantiate a first interface for operatively interfacing the data storage controller to the data storage device and to instantiate a second interface for operatively interfacing the data storage controller to a host system;
a non-volatile memory device, for storing logic code associated with the processor, the first interface and the second interface; and
a cache memory device for temporarily storing data that is processed by or transmitted through the data storage controller; wherein the processor further comprises a bandwidth allocation controller for controlling access to the cache memory device by the data compression engine, the first interface and the second interface.
2. The system of claim 1, wherein said data compression engine comprises a plurality of encoders in a parallel configuration.
3. The system of claim 1, wherein said processor, programmable logic device, non-volatile memory device, and cache memory device is located on an expansion bus card.
4. The system of claim 1, wherein said processor, programmable logic device, nonvolatile memory device, and cache memory device is located on a motherboard.
5. The system of claim 1, wherein at least said programmable logic device is located on an expansion bus card.
6. The system of claim 1, wherein said decompressing is performed by reading a data compression type descriptor and decompressing based on said data compression type descriptor.
7. The system of claim 1, wherein said compressing comprises providing a compression type descriptor indicative of the compression used to compress said data.
8. The system of claim 1, wherein said compressing comprises providing a compression type descriptor indicative of the compression used to compress said data and said compression type descriptor is indicative of utilizing a plurality of parallel encoders.
9. The system of claim 1, wherein said compressing comprises providing a compression type descriptor indicative of the compression used to compress said data and said compression type descriptor is indicative of utilizing a plurality of identical parallel encoders.
10. The system of claim 1, wherein said compressing comprises providing a compression type descriptor indicative of the compression used to compress said data and said compression type descriptor is indicative of utilizing a plurality of parallel encoders, wherein said plurality of parallel encoders are Lempel-Ziv encoders.
11. The system of claim 1, wherein said compressing comprises providing a compression type descriptor indicative of the compression used to compress said data and said compression type descriptor is indicative of utilizing a plurality of parallel encoders.
12. The system of claim 1, wherein said compressing achieves a ratio of approximately 3:1.
14. The system of claim 13, wherein said data compression engine comprises a plurality of encoders in a parallel configuration.
15. The system of claim 13, wherein said processor, programmable logic device, nonvolatile memory device, and cache memory device is located on an expansion bus card.
16. The system of claim 13, wherein said processor, programmable logic device, nonvolatile memory device, and cache memory device is located on a motherboard.
17. The system of claim 13, wherein at least said programmable logic device is located on an expansion bus card.
18. The system of claim 13, wherein said compressing comprises providing a compression type descriptor indicative of the compression used to compress said data.
19. The system of claim 13, wherein said compressing comprises providing a compression type descriptor indicative of the compression used to compress said data and said compression type descriptor is indicative of utilizing a plurality of parallel encoders.
20. The system of claim 13, wherein said compressing comprises providing a compression type descriptor indicative of the compression used to compress said data and said compression type descriptor is indicative of utilizing a plurality of identical parallel encoders.
21. The system of claim 13, wherein said compressing comprises providing a compression type descriptor indicative of the compression used to compress said data and said compression type descriptor is indicative of utilizing a plurality of parallel encoders, wherein said plurality of parallel encoders are Lempel-Ziv encoders.
22. The system of claim 13, wherein said compressing comprises providing a compression type descriptor indicative of the compression used to compress said data and said compression type descriptor is indicative of utilizing a plurality of parallel encoders.
23. The system of claim 13, wherein said compressing achieves a ratio of approximately 3:1.
24. The system of claim 13, wherein said compressing achieves a compression rate that increases the effective data storage rate of the target storage device.
25. The system of claim 13, wherein said compressing comprises a plurality of identical encoders in a parallel configuration and said compressing increases the effective data storage rate of the target storage device.

This application is a Continuation of U.S. patent application Ser. No. 10/306,581, filed on Nov. 27, 2002 which claims priority to U.S. Provisional Application Ser. No. 60/333,919, filed on Nov. 28, 2001, which is fully incorporated herein by reference, which is a Continuation-in-Part of U.S. patent application Ser. No. 09/775,905, filed Feb. 2, 2001 now U.S. Pat. No. 6,748,457, which claims priority to U.S. Provisional Application Ser. No. 60/180,114, filed on Feb. 3, 2000.

The present invention relates generally to systems and methods for data storage and retrieval and, more particularly, to data storage controllers employing lossless and/or lossy data compression and decompression to provide accelerated data storage and retrieval bandwidth.

Modern computers utilize a hierarchy of memory devices. To achieve maximum performance levels, modern processors utilize onboard memory and on board cache to obtain high bandwidth access to both program and data. Limitations in process technologies currently prohibit placing a sufficient quantity of onboard memory for most applications. Thus, in order to offer sufficient memory for the operating system(s), application programs, and user data, computers often use various forms of popular off-processor high speed memory including static random access memory (SRAM), synchronous dynamic random access memory (SDRAM), synchronous burst static ram (SBSRAM). Due to the prohibitive cost of the high-speed random access memory, coupled with their power volatility, a third lower level of the hierarchy exists for non-volatile mass storage devices.

Furthermore, mass storage devices offer increased capacity and fairly economical data storage. Mass storage devices (such as a “hard disk”) typically store the operating system of a computer system, as well as applications and data and rapid access to such data is critical to system performance. The data storage and retrieval bandwidth of mass storage devices, however, is typically much less as compared with the bandwidth of other elements of a computing system. Indeed, over the last decade, although computer processor performance has improved by at least a factor of 50, magnetic disk storage performance has only improved by a factor of 5. Consequently, memory storage devices severely limit the performance of consumer, entertainment, office, workstation, servers, and mainframe computers for all disk and memory intensive operations.

The explosion in the data storage market will require both an increase in disk densities as well as a reduction in overall size. This latter aspect, ongoing computer miniaturization will not only affect disk architectures but will create pressure to merge current individual functions into more optimized composite implementations.

The ubiquitous Internet combined with new multimedia applications has put tremendous emphasis on storage volumetric density, storage mass density, storewidth, and power consumption. Specifically, storage density is limited by the number of bits that are encoded in a mass storage device per unit volume. Similarly mass density is defined as storage bits per unit mass. Storewidth is the data rate at which the data may be accessed. There are various ways of categorizing storewidth in terms, several of the more prevalent metrics include sustained continuous storewidth, burst storewidth, and random access storewidth, all typically measured in megabytes/sec. Power consumption is canonically defined in terms of power consumption per bit and may be specified under a number of operating modes including active (while data is being accessed and transmitted) and standby mode. Hence one fairly obvious limitation within the current art is the need for even more volume, mass, and power efficient data storage.

Magnetic disk mass storage devices currently employed in a variety of home, business, and scientific computing applications suffer from significant seek-time access delays along with profound read/write data rate limitations. Currently the fastest available disk drives support only a sustained output data rate in the tens of megabytes per second data rate (MB/sec). This is in stark contrast to the modern Personal Computer's Peripheral Component Interconnect (PCI) Bus's low end 32 bit/33 Mhz input/output capability of 264 MB/sec and the PC's internal local bus capability of 800 MB/sec.

Another problem within the current art is that emergent high performance disk interface standards such as the Small Computer Systems Interface (SCSI-3), Fibre Channel, AT Attachment UltraDMA/66/100, Serial Storage Architecture, and Universal Serial Bus offer only higher data transfer rates through intermediate data buffering in random access memory. These interconnect strategies do not address the fundamental problem that all modern magnetic disk storage devices for the personal computer marketplace are still limited by the same typical physical media restrictions. In practice, faster disk access data rates are only achieved by the high cost solution of simultaneously accessing multiple disk drives with a technique known within the art as data striping and redundant array of independent disks (RAID).

RAID systems often afford the user the benefit of increased data bandwidth for data storage and retrieval. By simultaneously accessing two or more disk drives, data bandwidth may be increased at a maximum rate that is linear and directly proportional to the number of disks employed. Thus another problem with modern data storage systems utilizing RAID systems is that a linear increase in data bandwidth requires a proportional number of added disk storage devices.

Another problem with most modern mass storage devices is their inherent unreliability. Many modern mass storage devices utilize rotating assemblies and other types of electromechanical components that possess failure rates one or more orders of magnitude higher than equivalent solid-state devices. RAID systems employ data redundancy distributed across multiple disks to enhance data storage and retrieval reliability. In the simplest case, data may be explicitly repeated on multiple places on a single disk drive, on multiple places on two or more independent disk drives. More complex techniques are also employed that support various trade-offs between data bandwidth and data reliability.

Standard types of RAID systems currently available include RAID Levels 0, 1, and 5. The configuration selected depends on the goals to be achieved. Specifically data reliability, data validation, data storage/retrieval bandwidth, and cost all play a role in defining the appropriate RAID data storage solution. RAID level 0 entails pure data striping across multiple disk drives. This increases data bandwidth at best linearly with the number of disk drives utilized. Data reliability and validation capability are decreased. A failure of a single drive results in a complete loss of all data. Thus another problem with RAID systems is that low cost improved bandwidth requires a significant decrease in reliability.

RAID Level 1 utilizes disk mirroring where data is duplicated on an independent disk subsystem. Validation of data amongst the two independent drives is possible if the data is simultaneously accessed on both disks and subsequently compared. This tends to decrease data bandwidth from even that of a single comparable disk drive. In systems that offer hot swap capability, the failed drive is removed and a replacement drive is inserted. The data on the failed drive is then copied in the background while the entire system continues to operate in a performance degraded but fully operational mode. Once the data rebuild is complete, normal operation resumes. Hence, another problem with RAID systems is the high cost of increased reliability and associated decrease in performance.

RAID Level 5 employs disk data striping and parity error detection to increase both data bandwidth and reliability simultaneously. A minimum of three disk drives is required for this technique. In the event of a single disk drive failure, that drive may be rebuilt from parity and other data encoded on disk remaining disk drives. In systems that offer hot swap capability, the failed drive is removed and a replacement drive is inserted. The data on the failed drive is then rebuilt in the background while the entire system continues to operate in a performance degraded but fully operational mode. Once the data rebuild is complete, normal operation resumes.

Thus another problem with redundant modern mass storage devices is the degradation of data bandwidth when a storage device fails. Additional problems with bandwidth limitations and reliability similarly occur within the art by all other forms of sequential, pseudo-random, and random access mass storage devices. These and other limitations within the current art are addressed by the present invention.

The present invention is generally directed to data storage controllers and data storage devices employing lossless or lossy data compression and decompression to provide accelerated data storage and retrieval bandwidth. In one embodiment of the invention, a composite disk controller provides data storage and retrieval acceleration using multiple caches for data pipelining and increased throughput. In another embodiment of the invention, the disk controller with acceleration is embedded in the storage device and utilized for data storage and retrieval acceleration.

More particularly, in one aspect of the invention, a controller for controlling storage and retrieval of data to and from a data storage device comprises a data compression/decompression engine for compressing data stored to the data storage device and for decompressing data retrieved from the data storage device, a first cache, operatively connected to the storage device and the data compression/decompression engine, for temporary storage of (i) compressed data that is read from the data storage device and (ii) compressed data from the data compression/decompression engine that is to be written to the data storage device, a second cache, operatively connected to the data compression/decompression engine and to a host interface bus, for temporary storage of (i) data that is received from a host system over the host interface bus for compression and storage and (ii) data that is to be sent to the host system over the host interface bus, and a cache manager for controlling the first and second data caches under commands received from the data compression/decompression engine.

In another aspect, the first cache, second cache and the data compression/decompression engine are operatively connected by a first local bus and the data compression/decompression engine is connected to the cache manager over a dedicated bus.

In another aspect of the invention, a magnetic disk controller for controlling storage and retrieval of data to and from a magnetic disk comprises an embedded data compression/decompression engine for compressing data stored to the magnetic disk and for decompressing data retrieved from the magnetic disk, an embedded first cache, operatively connected to the magnetic disk and the data compression/decompression engine, for temporary storage of (i) compressed data that is read from the magnetic disk and (ii) compressed data from the data compression/decompression engine that is to be written to the magnetic disk, an embedded second cache, operatively connected to the data compression/decompression engine and to a host interface bus, for temporary storage of (i) data that is received from a host system over the host interface bus for compression and storage and (ii) data that is to be sent to the host system over the host interface bus, and an embedded cache manager for controlling the first and second data caches under commands received from the data compression/decompression engine.

In yet another aspect of the invention, a magnetic disk controller for controlling storage and retrieval of data to and from a magnetic disk comprises an embedded data compression/decompression engine for compressing data stored to the magnetic disk and for decompressing data retrieved from the magnetic disk, an embedded bi-directional cache for temporary storage of (i) compressed data that is read from the magnetic disk and (ii) compressed data from the data compression/decompression engine that is to be written to the magnetic disk, an embedded cache manager for controlling the bi-directional cache, and an embedded virtual file management system for mapping compressed data blocks stored on the disk to corresponding uncompressed data blocks.

The present invention is realized due to recent improvements in processing speed, inclusive of dedicated analog and digital hardware circuits, central processing units, (and any hybrid combinations thereof), that, coupled with advanced data compression and decompression algorithms are enabling of ultra high bandwidth data compression and decompression methods that enable improved data storage and retrieval bandwidth

These and other aspects, features and advantages, of the present invention will become apparent from the following detailed description of preferred embodiments that is to be read in connection with the accompanying drawings.

FIG. 1 is a block diagram of a data storage controller according to one embodiment of the present invention.

FIG. 2 is a block diagram of a data storage controller according to another embodiment of the present invention.

FIG. 3 is a block diagram of a data storage controller according to another embodiment of the present invention.

FIG. 4 is a block diagram of a data storage controller according to another embodiment of the present invention.

FIG. 5 is a block diagram of a data storage controller according to another embodiment of the present invention.

FIGS. 6a and 6b comprise a flow diagram of a method for initializing a data storage controller according to one aspect of the present invention.

FIGS. 7a and 7b comprise a flow diagram of a method for providing accelerated loading of an operating system and/or application programs upon system boot, according to one aspect of the present invention.

FIGS. 8a and 8b comprise a flow diagram of a method for providing accelerated loading of application programs according to one aspect of the present invention.

FIG. 9 is a diagram of an exemplary data compression system that may be employed in a data storage controller according to the present invention.

FIG. 10 is a diagram of an exemplary data decompression system that may be employed in a data storage controller according to the present invention.

FIG. 11 is a block diagram of a data storage controller according to another embodiment of the present invention.

FIG. 12 is a block diagram of a data storage controller according to another embodiment of the present invention.

FIG. 13 is a block diagram of a data storage device comprising an embedded data storage accelerator, according to an embodiment of the present invention.

In the following description, it is to be understood that system elements having equivalent or similar functionality are designated with the same reference numerals in the Figures. It is to be further understood that the present invention may be implemented in various forms of hardware, software, firmware, or a combination thereof. Preferably, the present invention is implemented on a computer platform including hardware such as one or more central processing units (CPU) or digital signal processors (DSP), a random access memory (RAM), and input/output (I/O) interface(s). The computer platform may also include an operating system, microinstruction code, and dedicated processing hardware utilizing combinatorial logic or finite state machines. The various processes and functions described herein may be either part of the hardware, microinstruction code or application programs that are executed via the operating system, or any combination thereof.

It is to be further understood that, because some of the constituent system components described herein are preferably implemented as software modules, the actual system connections shown in the Figures may differ depending upon the manner in that the systems are programmed. It is to be appreciated that special purpose microprocessors, dedicated hardware, or and combination thereof may be employed to implement the present invention. Given the teachings herein, one of ordinary skill in the related art will be able to contemplate these and similar implementations or configurations of the present invention.

I. System Architectures

The present invention is directed to data storage controllers that provide increased data storage/retrieval rates that are not otherwise achievable using conventional disk controller systems and protocols to store/retrieve data to/from mass storage devices. The concept of “accelerated” data storage and retrieval was introduced in U.S. patent application Ser. No. 09/266,394, filed Mar. 11, 1999, entitled “System and Methods For Accelerated Data Storage and Retrieval”, which is now U.S. Pat. No. 6,601,104 and U.S. patent application Ser. No. 09/481,243, filed Jan. 11, 2000, entitled “System and Methods For Accelerated Data Storage and Retrieval,” which is now U.S. Pat. No. 6,604,158, both of which are commonly assigned and incorporated herein by reference. In general, as described in the above-incorporated applications, “accelerated” data storage comprises receiving a digital data stream at a data transmission rate which is greater that the data storage rate of a target storage device, compressing the input stream at a compression rate that increases the effective data storage rate of the target storage device and storing the compressed data in the target storage device. For instance, assume that a mass storage device (such as a hard disk) has a data storage rate of 20 megabytes per second. If a storage controller for the mass storage device is capable of compressing an input data stream with an average compression rate of 3:1, then data can be stored in the mass storage device at a rate of 60 megabytes per second, thereby effectively increasing the storage bandwidth (“storewidth”) of the mass storage device by a factor of three. Similarly, accelerated data retrieval comprises retrieving a compressed digital data stream from a target storage device at the rate equal to, e.g., the data access rate of the target storage device and then decompressing the compressed data at a rate that increases the effective data access rate of the target storage device. Advantageously, accelerated data storage/retrieval mitigates the traditional bottleneck associated with, e.g., local and network disk accesses.

Referring now to FIG. 1, a high-level block diagram illustrates a data storage controller 10 according to one embodiment of the present invention. The data storage controller 10 comprises a data compression engine 12 for compressing/decompressing data (preferably in real-time or psuedo real-time) stored/retrieved from a hard disk 11 (or any other type of mass storage device) to provide accelerated data storage/retrieval. The DCE 12 preferably employs the data compression/decompression techniques disclosed in U.S. Pat. No. 6,195,024, issued on Feb. 27, 2001, entitled “Content Independent Data Compression Method and System,” which is commonly assigned and which is fully incorporated herein by reference. It is to be appreciated that the compression and decompression systems and methods disclosed in U.S. Pat. No. 6,195,024 are suitable for compressing and decompressing data at rates, which provide accelerated data storage and retrieval. A detailed discussion of a preferred “content independent” data compression process will be provided below.

The data storage controller 10 further comprises a cache 13, a disk interface (or disk controller) 14 and a bus interface 15. The storage controller 10 is operatively connected to the hard disk 12 via the disk controller 14 and operatively connected to an expansion bus (or main bus) 16 of a computer system via the bus interface 15. The disk interface 14 may employ a known disk interface standard such as UltraDMA, SCSI, Serial Storage Architecture, FibreChannel or any other interface that provides suitable disk access data rates. In addition, the storage controller 10 preferably utilizes the American National Standard for Information Systems (ANSI) AT Attachment Interface (ATA/ATAPI-4) to connect the data storage controller 10 to the hard disk 12. As is known in the art, this standard defines the connectors and cables for the physical interconnects between the data storage controller and the storage devices, along with the electrical and logical characteristics of the interconnecting signals.

Further, the bus interface 15 may employ a known standard such as the PCI (Peripheral Component Interconnect) bus interface for interfacing with a computer system. The use of industry standard interfaces and protocols is preferable, as it allows the storage controller 10 to be backwards compatible and seamlessly integrated with current systems. However in new designs the present invention may be utilize any suitable computer interface or combination thereof.

It is to be understood that although FIG. 1 illustrates a hard disk 12, the storage controller 10 may be employed with any form of memory device including all forms of sequential, pseudo-random, and random access storage devices. Storage devices as known within the current art include all forms of random access memory, magnetic and optical tape, magnetic and optical disks, along with various other forms of solid-state mass storage devices. The current invention applies to all forms and manners of memory devices including, but not limited to, storage devices utilizing magnetic, optical, and chemical techniques, or any combination thereof. In addition, the cache 13 may comprise volatile or non-volatile memory, or any combination thereof. Preferably, the cache 13 is implemented in SDRAM (static dynamic random access memory).

The system of FIG. 1 generally operates as follows. When data is read from disk by the host computer, data flows from the disk 11 through the data storage controller 10 to the host computer. Data is stored in one of several proprietary compression formats on the disk 11 (e.g., “content independent” data compression). Data blocks are pre-specified in length, comprised of single or multiple sectors, and are typically handled in fractional or whole equivalents of tracks, e.g. ½ track, whole track, multiple tracks, etc. To read disk data, a DMA transfer is setup from the disk interface 14 to the onboard cache memory 13. The disk interface 14 comprises integral DMA control to allow transfer of data from the disk 11 directly to the onboard cache 13 without intervention by the DCE 12. It should be noted that the DCE 12 acts as a system level controller and sets-up specific registers within both the disk interface 14 and bus interface 15 to facilitate DMA transfers to and from the cache memory 13. To initiate a transfer from the disk 11 to the cache 13, the DMA transfer is setup via specifying the appropriate command (read disk), the source address (disk logical block number), amount of data to be transferred (number of disk logical blocks), and destination address within the onboard cache memory 13. Then, a disk data interrupt signal (“DISKINT#”) is cleared (if previously set and not cleared) and the command is initiated by writing to the appropriate address space. Once data has been read from disk 11 and placed into onboard cache memory 13, the DISKINT# interrupt is asserted notifying the DCE 12 that requested data is now available in the cache memory 13. Data is then read by the DMA controller within the DCE 12 and placed into local memory for subsequent decompression. The decompressed data is then DMA transferred from the local memory of the DCE 12 back to the cache memory 13. Finally, data is DMA transferred via the bus interface controller 15 from the cache memory 13 to the bus 16. It is to be understood that in the read mode, the data storage controller acts as a bus master. A bus DMA transfer is then setup via specifying the appropriate command (write to host computer), the source address within the cache memory 13, the quantity of data words to be transferred (transfers are preferably in 4 byte increments), and the destination address on the host computer. When a bus 16 read or write transaction has completed, the appropriate interrupt signals (respectively referred to as PCIRDINT# and PCIWRINT#) are asserted to the DCE 12. Either of these interrupts are cleared by a corresponding interrupt service routines through a read or write to the appropriate address of the DCE 12.

Similarly, when data is written to the disk 11 from the host computer, data flows from the host computer through the data storage controller 10 and onto disk 11. Data is normally received from the host computer in uncompressed (raw) format and is compressed by the DCE 12 and stored on the disk 11. Data blocks from the host are pre-specified in length and are typically handled in blocks that are a fixed multiplier higher than fractional or whole equivalents of tracks, e.g. ½ track, whole track, multiple tracks, etc. This multiplier is preferably derived from the expected average compression ratio that is selected when the disk is formatted with the virtual file management system. To read host computer data, a bus DMA transfer is setup from the host bus 16 to the onboard cache memory 13. The bus interface controller 15 comprises integral DMA control that allows large block transfers from the host computer directly to the onboard cache 13 without intervention by the DCE 12. The bus interface controller 15 acts as a host computer Bus Master when executing such transfer. Once data has been read from the host and placed into onboard cache memory 13, the data is read by the onboard DMA controller (residing on the DCE 12) and placed into local memory for subsequent compression. The compressed data is then DMA transferred from the local memory of the DCE 12 back to the cache memory 13. Finally, data is DMA transferred via the disk controller 14 from the cache 13 to the disk 11.

As discussed in greater detail below, upon host computer power-up or external user reset, the data storage controller 10 initializes the onboard interfaces 14, 5 prior to release of the external host bus 16 from reset. The processor of the host computer then requests initial data from the disk 11 to facilitate the computer's boot-up sequence. The host computer requests disk data over the Bus 16 via a command packet issued from the host computer. Command packets are preferably eight words long (in a preferred embodiment, each word comprises 32 bits). Commands are written from the host computer to the data storage controller 10 with the host computer as the Bus Master and the data storage controller 10 as the slave. The data storage controller 10 includes at least one Base Address Register (BAR) for decoding the address of a command queue of the data storage controller 10. The command queue resides within the cache 13 or within onboard memory of the DCE 12.

When a command is received from the host computer, an interrupt (referred to herein as PCICMDINT#) is generated to the DCE processor. The eight-word command is read by the DCE 12 and placed into the command queue. Because the commands occupy a very small amount of memory, the location of the command queue is at the discretion of software and the associated system level performance considerations. Commands may be moved from the bus interface 16 to the command queue by wither explicit reads and writes by the DCE processor or, as explained below, by utilizing programmed DMA from an Enhanced DMA Controller (EDMA) residing on the DCE 12. This second technique may better facilitate system throughput by allowing the EDMA to automatically load commands while the highly pipelined data compression and decompression processing in the DCE is executed fully undisturbed.

The DCE 12, disk interface 14 and bus interface 15 commonly share the cache 13. As explained in detail below, the storage controller 10 preferably provides maximum system bandwidth by allowing simultaneous data transfers between the disk 12 and cache 13, the DCE 12 and the cache 13, and the expansion bus 16 and the cache 13. This is realized by employing an integral DMA (direct memory access) protocol that allows the DCE 12, disk interface 14 and bus interface 15 to transfer data without interrupting or interfering with other ongoing processes. In particular, as explained in detail below, an integral bandwidth allocation controller (or arbitrator) is preferably employed to allow the DCE 12, disk controller 14, and bus interface 15 to access the onboard cache with a bandwidth proportional to the overall bandwidth of the respective interface or processing element. The bandwidth arbitration occurs transparently and does not introduce latency in memory accesses. Bandwidth division is preferably performed with a high degree of granularity to minimize the size of requisite onboard buffers to synchronize data from the disk interface 14 and bus interface 15.

It is to be appreciated that the implementation of a storage controller according to the present invention significantly accelerates the performance of a computer system and significantly increases hard disk data storage capacity. For instance, depending on the compression rate, for personal computers running standard Microsoft Windows® based business application software, the storage controller provides: (1) an increase of n:1 in disk storage capacity (for example, assuming a compression ration of 3:1, a 20 gigabyte hard drive effectively becomes a 60 gigabyte hard drive) (2) a significant decrease in the computer boot-up time (turn-on and operating system load) and the time for loading application software and (3) User data storage and retrieval is increased by a factor of n:1.

Referring now to FIG. 2, a block diagram illustrates a data storage controller 20 according to another embodiment of the present invention. More specifically, FIG. 2 illustrates a PCB (printed circuit board) implementation of the data storage controller 10 of FIG. 1. The storage controller 20 comprises a DSP (digital signal processor) 21 (or any other micro-processor device) that implements the DCE 12 of FIG. 1. The storage controller 21 further comprises at least one programmable logic device 22 (or volatile logic device). The programmable logic device 22 preferably implements the logic (program code) for instantiating and driving both the disk interface 14 and the bus interface 15 and for providing full DMA capability for the disk and bus interfaces 14, 15. Further, as explained in detail below, upon host computer power-up and/or assertion of a system-level “reset” (e.g., PCI Bus reset), the DSP 21 initializes and programs the programmable logic device 22 before of the completion of initialization of the host computer. This advantageously allows the data storage controller 20 to be ready to accept and process commands from the host computer (via the bus 16) and retrieve boot data from the disk (assuming the data storage controller 20 is implemented as the boot device and the hard disk stores the boot data (e.g., operating system, etc.)).

The data storage controller 20 further comprises a plurality of memory devices including a RAM (random access memory) device 23 and a ROM (read only memory) device 24 (or FLASH memory or other types of non-volatile memory). The RAM device 23 is utilized as on-board cache and is preferably implemented as SDRAM (preferably, 32 megabytes minimum). The ROM device 24 is utilized for non-volatile storage of logic code associated with the DSP 21 and configuration data used by the DSP 21 to program the programmable logic device 22. The ROM device 24 preferably comprises a one time (erasable) programmable memory (OTP-EPROM) device.

The DSP 21 is operatively connected to the memory devices 23, 24 and the programmable logic device 22 via a local bus 25. The DSP 21 is also operatively connected to the programmable logic device 22 via an independent control bus 26. The programmable logic device 22 provides data flow control between the DSP 21 and the host computer system attached to the bus 16, as well as data flow control between the DSP 21 and the storage device. A plurality of external I/O ports 27 are included for data transmission and/or loading of one programmable logic devices. Preferably, the disk interface 14 driven by the programmable logic device 22 supports a plurality of hard drives.

The storage controller 20 further comprises computer reset and power up circuitry 28 (or “boot configuration circuit”) for controlling initialization (either cold or warm boots) of the host computer system and storage controller 20. A preferred boot configuration circuit and preferred computer initialization systems and protocols are described in U.S. patent application Ser. No. 09/775,897, filed on Feb. 2, 2001, entitled “Systems and Methods for Computer Initialization”, which is commonly assigned and incorporated herein by reference. Preferably, the boot configuration circuit 28 is employed for controlling the initializing and programming the programmable logic device 22 during configuration of the host computer system (i.e., while the CPU of the host is held in reset). The boot configuration circuit 28 ensures that the programmable logic device 22 (and possibly other volatile or partially volatile logic devices) is initialized and programmed before the bus 16 (such as a PCI bus) is fully reset.

In particular, when power is first applied to the boot configuration circuit 28, the boot configuration circuit 28 generates a control signal to reset the local system (e.g., storage controller 20) devices such as a DSP, memory, and I/O interfaces. Once the local system is powered-up and reset, the controlling device (such as the DSP 21) will then proceed to automatically determine the system environment and configure the local system to work within that environment. By way of example, the DSP 21 of the disk storage controller 20 would sense that the data storage controller 20 is on a PCI computer bus (expansion bus) and has attached to it a hard disk on an IDE interface. The DSP 21 would then load the appropriate PCI and IDE interfaces into the programmable logic device 22 prior to completion of the host system reset. It is to be appreciated that this can be done for all computer busses and boot device interfaces including: PCI, NuBus, ISA, Fiber Channel, SCSI, Ethernet, DSL, ADSL, IDE, DMA, Ultra DMA, and SONET. Once the programmable logic device 22 is configured for its environment, the boot device controller is reset and ready to accept commands over the computer/expansion bus 16. Details of the boot process using a boot device comprising a programmable logic device will be provided below.

It is to be understood that the data storage controller 20 may be utilized as a controller for transmitting data (compressed or uncompressed) to and from remote locations over the DSP I/O ports 27 or system bus 16, for example. Indeed, the I/O ports 27 of the DSP 21 may be used for transmitting data (compressed or uncompressed) that is either retrieved from the disk 11 or received from the host system via the bus 16, to remote locations for processing and/or storage. Indeed, the I/O ports may be operatively connected to other data storage controllers or to a network communication channels. Likewise, the data storage controller 20 may receive data (compressed or uncompressed) over the I/O ports 27 of the DSP 21 from remote systems that are connected to the I/O ports 27 of the DSP, for local processing by the data storage controller 20. For instance, a remote system may remotely access the data storage controller (via the I/O ports of the DSP or system bus 16) to utilize the data compression, in which case the data storage controller would transmit the compressed data back to the system that requested compression.

The DSP 21 may comprise any suitable commercially available DSP or processor. Preferably, the data storage controller 20 utilizes a DSP from Texas Instruments' 320 series, C62x family, of DSPs (such as TMS320C6211GFN-150), although any other DSP or processor comprising a similar architecture and providing similar functionalities may be employed. The preferred DSP is capable of up to 1.2 billion instructions per second. Additional features of the preferred DSP include a highly parallel eight processor single cycle instruction execution, onboard 4K byte LIP Program Cache, 4K LID Data Cache, and 64K byte Unified L2 Program/Data Cache. The preferred DSP further comprises a 32 bit External Memory Interface (EMIF) that provides for a glueless interface to the RAM 23 and the non-volatile memory 24 (ROM). The DSP further comprises two multi-channel buffered serial ports (McBSPs) and two 32 bit general purpose timers. Preferably, the storage controller disables the I/O capability of these devices and utilizes the I/O ports of the DSP as general purpose I/O for both programming the programmable logic device 22 using a strobed eight bit interface and signaling via a Light Emitting Diode (LED). Ancillary DSP features include a 16 bit Host Port Interface and full JTAG emulation capability for development support.

The programmable logic device 22 may comprise any form of volatile or non-volatile memory. Preferably, the programmable logic device 22 comprises a dynamically reprogrammable FPGA (field programmable gate array) such as the commercially available Xilinx Spartan Series XCS40XL-PQ240-5 FPGA. As discussed in detail herein, the FPGA instantiates and drives the disk and bus interfaces 14, 15.

The non-volatile memory device 24 preferably comprises a 128 Kbyte M27W101-80K one time (erasable) programmable read only memory, although other suitable non-volatile storage devices may be employed. The non-volatile memory device 24 is decoded at a designated memory space in the DSP 21. The non-volatile memory device 24 stores the logic for the DSP 21 and configuration data for the programmable logic device 22. More specifically, in a preferred embodiment, the lower 80 Kbytes of the non-volatile memory device 24 are utilized for storing DSP program code, wherein the first 1k bytes are utilized for the DSP's boot loader. Upon reset of the DSP 21 (via boot configuration circuit 28), the first 1K of memory of the non-volatile memory device 24 is copied into an internal RAM of the DSP 21 by e.g., the DSP's Enhanced DMA Controller (EDMA). Although the boot process begins when the CPU of the host system is released from external reset, the transfer of the boot code into the DSP and the DSP's initialization of the programmable logic device actually occurs while the CPU of the host system is held in reset. After completion of the 1K block transfer, the DSP executes the boot loader code and continues thereafter with executing the remainder of the code in non-volatile memory device to program the programmable logic device 22.

More specifically, in a preferred embodiment, the upper 48K bytes of the non-volatile memory device 24 are utilized for storing configuration data associated with the programmable logic device 22. If the data storage controller 20 is employed as the primary boot storage device for the host computer, the logic for instantiating and driving the disk and bus interfaces 14, 15 should be stored on the data storage controller 20 (although such code may be stored in remotely accessible memory locations) and loaded prior to release of the host system bus 16 from “reset”. For instance, revision 2.2 of the PCI Local Bus specification calls for a typical delay of 100 msec from power-stable before release of PCI Reset. In practice this delay is currently 200 msec although this varies amongst computer manufacturers. A detailed discussion of the power-on sequencing and boot operation of the data storage controller 20 will be provided below.

FIG. 3 illustrates another embodiment of a data storage controller 30 wherein the data storage controller 35 is embedded within the motherboard of the host computer system. This architecture provides the same functionality as the system of FIG. 2, and also adds the cost advantage of being embedded on the host motherboard. The system comprises additional RAM and ROM memory devices 23a, 24a, operatively connected to the DSP 21 via a local bus 25a.

FIG. 4 illustrates another embodiment of a data storage controller. The data storage controller 40 comprises a PCB implementation that is capable of supporting RAID levels 0,1 and 5. This architecture is similar to those of FIGS. 1 and 2, except that a plurality of programmable logic devices 22, 22a are utilized. The programmable logic device 22 is dedicated to controlling the bus interface 15. The programmable logic device 22a is dedicated to controlling a plurality of disk interfaces 14, preferably three interfaces. Each disk interface 14 can connect up to two drives. The DSP in conjunction with the programmable logic device 22a can operate at RAID level 0, 1 or 5. At RAID level 0, which is disk striping, two interfaces are required. This is also true for RAID level 1, which is disk mirroring. At RAID level 5, all three interfaces are required.

FIG. 5 illustrates another embodiment of a data storage controller according to the present invention. The data storage controller 45 provides the same functionality as that of FIG. 4, and has the cost advantage of being embedded within the computer system motherboard.

II. Initializing A Programmable Logic Device

As discussed above with reference to FIG. 2, for example, the data storage controller 20 preferably employs an onboard Texas Instruments TMS320C6211 Digital Signal Processor (DSP) to program the onboard Xilinx Spartan Series XCS40XL FPGA upon power-up or system level PCI reset. The onboard boot configuration circuit 28 ensures that from system power-up and/or the assertion of a bus reset (e.g., PCI reset), the DSP 21 is allotted a predetermined amount of time (preferably a minimum of 10 msec) to boot the DSP 21 and load the programmable logic device 22. Because of a potential race condition between either the host computer power-up or assertion of PCI Bus reset and configuration of the programmable logic device 20 (which is used for controlling the boot device and accepting PCI Commands), an “Express Mode” programming mode for configuring the SpartanXL family XCS40XL device is preferably employed. The XCS40XL is factory set to byte-wide Express-Mode programming by setting both the M1/M0 bits of the XCS40XL to 0×0. Further, to accommodate express mode programming of the programmable logic device 22, the DSP 21 is programmed to utilize its serial ports reconfigured as general purpose I/O. However, after the logic device 22 is programmed, the DSP 21 may then reconfigure its serial ports for use with other devices. Advantageously, using the same DSP ports for multiple purposes affords greater flexibility while minimizing hardware resources and thus reducing product cost.

The volatile nature of the logic device 22 effectively affords the ability to have an unlimited number of hardware interfaces. Any number of programs for execution by the programmable logic device 22 can be kept in an accessible memory location (EPROM, hard disk, or other storage device). Each program can contain new disk interfaces, interface modes or subsets thereof. When necessary, the DSP 21 can clear the interface currently residing in the logic device 22 and reprogram it with a new interface. This feature allows the data storage controller 20 to have compatibility with a large number of interfaces while minimizing hardware resources and thus reducing product cost.

A preferred protocol for programming the programmable logic device can be summarized in the following steps: (1) Clearing the configuration memory; (2) Initialization; (3) Configuration; and (4) Start-Up. When either of three events occur: the host computer is first powered-up or a power failure and subsequent recovery occurs (cold boot), or a front panel computer reset is initiated (warm boot), the host computer asserts RST# (reset) on the PCI Bus. As noted above, the data storage controller 20 preferably comprises a boot configuration circuit 28 that senses initial host computer power turn-on and/or assertion of a PCI Bus Reset (“PCI RST#”). It is important to note that assuming the data storage controller 20 is utilized in the computer boot-up sequence, it should be available exactly 5 clock cycles after the PCI RST# is deasserted, as per PCI Bus Specification Revision 2.2. While exact timings vary from computer to computer, the typical PCI bus reset is asserted for approximately 200 msec from initial power turn-on.

In general, PCI RST# is asserted as soon as the computer's power exceeds a nominal threshold of about 1 volt (although this varies) and remains asserted for 200 msec thereafter. Power failure detection of the 5 volt or 3.3 volt bus typically resets the entire computer as if it is an initial power-up event (i.e., cold boot). Front panel resets (warm boots) are more troublesome and are derived from a debounced push-button switch input. Typical front panel reset times are a minimum of 20 msec, although again the only governing specification limit is 1 msec reset pulse width.

As discussed in detail below, it may not be necessary to reload the programmable logic device 22 each time the DSP is reset. The boot configuration circuit 20 preferably comprises a state machine output signal that is readable by the DSP 21 to ascertain the type of boot process requested. For example, with a front-panel reset (warm boot), the power remains stable on the PCI Bus, thus the programmable logic device 22 should not require reloading.

Referring now to FIG. 6, a flow diagram illustrates a method for initializing the programmable logic device 22 according to one aspect of the invention. In the following discussion, it is assumed that the programmable logic device 22 is always reloaded, regardless of the type of boot process. Initially, in FIG. 6a, the DSP 21 is reset by asserting a DSP reset signal (step 50). Preferably, the DSP reset signal is generated by the boot circuit configuration circuit 28 (as described in the above-incorporated U.S. patent application Ser. No. 09/775,897). While the DSP reset signal is asserted (e.g., active low), the DSP is held in reset and is initialized to a prescribed state. Upon deassertion of the DSP Reset signal, the logic code for the DSP (referred to as the “boot loader”) is copied from the non-volatile logic device 24 into memory residing in the DSP 21 (step 51). This allows the DSP to execute the initialization of the programmable logic device 22. In a preferred embodiment, the lower 1K bytes of EPROM memory is copied to the first 1k bytes of DSP's low memory (0×0000 0000 through 0×0000 03FF). As noted above, the memory mapping of the DSP 21 maps the CE1 memory space located at 0×9000 0000 through 0x9001 FFFF with the OTP EPROM. In a preferred embodiment using the Texas Instrument DSP TMS320c6211GFN-150, this ROM boot process is executed by the EDMA controller of the DSP. It is to be understood, however, that the EDMA controller may be instantiated in the programmable logic device (Xilinx), or shared between the DSP and programmable logic device.

After the logic is loaded in the DSP 21, the DSP 21 begins execution out of the lower 1K bytes of memory (step 52). In a preferred embodiment, the DSP 21 initializes with at least the functionality to read EPROM Memory (CE1) space. Then, as described above, the DSP preferably configures its serial ports as general purpose I/O (step 53).

Next, the DSP 21 will initialize the programmable logic device 22 using one or more suitable control signals. (step 54). After initialization, the DSP 21 begins reading the configuration data of the programmable logic device 22 from the non-volatile memory 24 (step 55). This process begins with clearing a Data Byte Counter and then reading the first data byte beginning at a prespecified memory location in the non-volatile memory 24 (step 56). Then, the first output byte is loaded into the DSP's I/O locations with LSB at D0 and MSB at D7 (step 57). Before the first byte is loaded to the logic device 22, a prespecified time delay (e.g., 5 usec) is provided to ensure that the logic device 22 has been initialized (step 58). In particular, this time delay should be of a duration at least equal to the internal setup time of the programmable logic device 22 from completion of initialization. Once this time delay has expired, the first data byte in the I/O bus 26 of the DSP 21 is latched into the programmable logic device 22 (step 59).

Next, a determination is made as to whether the Data Byte Counter is less than a prespecified value (step 60). If the Data Byte Counter is less than the prespecified value (affirmative determination in step 60), the next successive data byte for the programmable logic device 22 is read from the non-volatile memory 24 (step 61) and the Data Byte Counter is incremented (step 62).

Next, the read data byte is loaded into the I/O of the DSP (step 63). A time delay of, e.g., 20 nsec is allowed to expire before the data byte is latched to the programmable logic device to ensure that a minimum data set-up time to the programmable logic device 21 is observed (step 64) and the process is repeated (return to step 60). It is to be appreciated that steps 60-64 may be performed while the current data byte is being latched to the programmable logic device. This provides “pipeline” programming of the logic device 22 and minimizes programming duration.

When the Data Byte Counter is not less than the prespecified count value negative determination in step 60), as shown in FIG. 6b, the last data byte is read from the non-volatile memory and latched to the programmable logic device 22, and the DSP 21 will then poll a control signal generated by the programmable logic device 22 to ensure that the programming of the logic device 22 is successful (step 65). If programming is complete (affirmative determination in step 66), the process continues with the remainder of the data storage controller initialization (step 67). Otherwise, a timeout occurs (step 68) and upon expiration of the timeout, an error signal is provided and the programming process is repeated (step 69).

III. Data Storage and Retrieval Protocols

A detailed discussion of operational modes of a data storage controller will now be provided with reference to the embodiment of FIG. 2 (although it is to be understood that the following discussion is applicable to all the above-described embodiments). The data storage controller 20 utilizes a plurality of commands to implement the data storage, retrieval, and disk maintenance functions described herein. Each command preferably comprises eight thirty-two bit data words stored and transmitted in little endian format. The commands include: Read Disk Data; Write Disk Data; and Copy Disk Data, for example. For example, a preferred format for the “Read Disk Data” command is:

##STR00001##

The host computer commands the data storage controller 20 over the PCI Bus 16, for example. Upon computer power-up or reset, the host computer issues a PCI Bus Reset with a minimum pulse width of 100 msec (in accordance with PCI Bus Specification Revision 2.2). Upon completion of the PCI Bus reset, the data storage controller 20 is fully initialized and waiting for completion of the PCI configuration cycle. Upon completion of the PCI configuration cycles, the data storage controller will wait in an idle state for the first disk command.

During operation, the host operating system may issue a command to the data storage controller 20 to store, retrieve, or copy specific logical data blocks. Each command is transmitted over the PCI Bus 16 at the Address assigned to the Base Address Register (BAR) of the data storage controller 20.

The commands issued by the host system to the data storage controller and the data transmitted to and from the data storage controller are preferably communicated via a 32 bit, 33 MHz, PCI Data Bus. As noted above, the PCI Interface is preferably housed within the onboard Xilinx Spartan XCS40XL-5 40,000 field programmable gate array which instantiates a PCI 32, 32 Bit, 33 MHz PCI Bus Interface (as per PCI Bus Revision 2.2).

The PCI Bus interface operates in Slave Mode when receiving commands and as a Bus Master when reading or writing data. The source and destination for all data is specified within each command packet. When setting up data transfers, the Enhanced Direct Memory Access (EDMA) Controller of the DSP (or the Xilinx) utilizes two Control Registers, a 16 Word Data Write to PCI Bus FIFO, a 16 Word Data Read From PCI Bus FIFO, and a PCI Data Interrupt (PCIDATINT). The 32 Bit PCI Address Register holds either the starting Source Address for data storage controller Disk Writes where data is read from the PCI Bus, or the starting Destination Address for data storage controller Disk Reads where data is written to the PCI Bus. The second control register is a PCI Count Register that specifies the direction of the data transfer along with the number of 32 bit Data words to be written to or from the PCI bus.

Data is written to the PCI Bus from the DSP via a 16 Word PCI Data Write FIFO located within a prespecified address range. Data writes from the DSP to anywhere within the address range place that data word in the next available location within the FIFO. Data is read from the PCI Bus to the DSP via a 16 Word PCI Data Read FIFO located within a prespecified address range and data read by the DSP from anywhere within this address range provides the next data word from the FIFO.

After completion of the Xilinx initialization by the DSP and subsequent negation of the PCI Bus Reset signal (RST#) by the host computer's PCI Bridge, the data storage controller is ready to accept commands from the host computer via the PCI Bus. When accepting commands it should be noted that the data storage controller is a PCI Target (Slave) Device. Commands are preferably fixed in length at exactly 8 (thirty-two bit) words long. Commands are written from the host computer to the data storage controller via the PCI Bus utilizing the data storage controller's Base Address Register 0 (BAR0). The PCI Bus Reset initially sets the Command FIFO's Counter to zero and also signals the Xilinx's PCI Bus State Controller that the Command FIFO is empty and enable to accept a command.

Whenever a data write occurs within the valid data range of BAR0, the data word is accepted from PCI Bus and placed in the next available memory position within the Command FIFO. When the last of the 8 thirty-two bit data words is accepted by the PCI Bus (thus completing the command, i.e. last word for the command FIFO to be full), the PCI Bus State Controller is automatically set to Target Abort (within same PCI Transaction) or Disconnect Without Data for all subsequent PCI transactions that try to writes to BAR0. This automatic setting is the responsibility of the Xilinx PCI Data Interface.

The PCI Command FIFO State Controller then asserts the Command Available Interrupt to the DSP. The DSP services the Command Available Interrupt by reading the command data from a prespecified address range. It should be noted that the command FIFO is read sequentially from any data access that reads data within such address range. It is the responsibility of the DSP to understand that the data is read sequentially from any order of accesses within the data range and should thus be stored accordingly.

Upon completion of the Command Available Interrupt Service Routine the DSP executes a memory read or write to desired location within the PCI Control Register Space mapped into the DSP's CE3 (Xilinx) memory space. This resets the Command FIFO Counter back to zero. Next, the DSP executes a memory read or write to location in the DSP Memory Space that clears the Command Available Interrupt. Nested interrupts are not possible since the PCI Bus State Machine is not yet able to accept any Command Data at BAR0. Once the Command Available Interrupt routine has cleared the interrupt and exited, the DSP may then enable the PCI State Machine to accept a new command by reading or writing to PCI Command Enable location within the PCI Command FIFO Control Register Space.

A preferred architecture has been selected to enable the data storage controller to operate on one command at a time or to accept multiple prioritized commands in future implementations. Specifically, the decoupling of the Command Available Interrupt Service Routine from the PCI State Machine that accepts Commands at BAR0 enables the DSP's “operating system kernel” to accept additional commands at any time by software command. In single command operation, a command is accepted, the Command Available Interrupt Cleared, and the Command executed by the data storage controller in PCI Master Mode prior to the enabling of the PCI State machine to accept new commands.

In a prioritized multi-command implementation, the “operating system kernel” may elect to immediately accept new commands or defer the acceptance of new commands based upon any software implemented decision criteria. In one embodiment, the O/S code might only allow a pre-specified number of commands to be queued. In another embodiment, commands might only be accepted during processor idle time or when the DSP is not executing time critical (i.e. highly pipelined) compress/decompress routines. In yet another embodiment, various processes are enabled based upon a pre-emptive prioritized based scheduling system.

As previously stated, the data storage controller retrieves commands from the input command FIFO in 8 thirty-two bit word packets. Prior to command interpretation and execution, a command's checksum value is computed to verify the integrity of the data command and associated parameters. If the checksum fails, the host computer is notified of the command packet that failed utilizing the Command Protocol Error Handler. Once the checksum is verified the command type and associated parameters are utilized as an offset into the command “pointer” table or nay other suitable command/data structure that transfers control to the appropriate command execution routine.

Commands are executed by the data storage controller with the data storage controller acting as a PCI Master. This is in direct contrast to command acceptance where the data storage controller acts as a PCI Slave. When acting as a PCI Bus Master, the data storage controller reads or writes data to the PCI Bus utilizing a separate PCI Bus Data FIFO (distinct & apart from the Command FIFO). The PCI Data FIFO is 64 (thirty-two bit) words deep and may be utilized for either data reads or data writes from the DSP to the PCI Bus, but not both simultaneously.

For data to be written from the data storage controller to the Host Computer, the DSP must first write the output data to the PCI Bus Data FIFO. The Data FIFO is commanded to PCI Bus Data Write Mode by writing to a desired location within the Xilinx (CE3) PCI Control Register Space. Upon PCI Bus Reset the default state for the PCI Data FIFO is write mode and the PCI Data FIFO Available Interrupt is cleared. The PCI Data FIFO Available Interrupt should also be software cleared by writing to a prespecified location. Preferably, the first task for the data storage controller is for system boot-up or application code to be downloaded from disk. For reference, PCI Data Read Mode is commanded by writing to location BFF0 0104. The PCI Bus Reset initializes the Data FIFO Pointer to the first data of the 64 data words within the FIFO. However this pointer should always be explicitly initialized by a memory write to location BFF0 0108. This ensures that the first data word written to the FIFO by the DSP performing the data write anywhere in address range B000 0000 to B000 01FF is placed at the beginning of the FIFO. Each subsequent write to any location within this address range then places one thirty-two bit data word into the next available location within the PCI Data FIFO. The FIFO accepts up to 64 thirty-two bit data words although it should be clearly understood that not all data transfers to and from the PCI Bus will consist of a full FIFO. Counting the number of thirty-two bit data words written to the PCI Data FIFO is the responsibility of the DSP Code. It is envisioned that the DSP will, in general, use 64 word DMA data transfers, thus alleviating any additional processor overhead.

When the data has been transferred from the DSP to the PCI Data FIFO, the PCI Bus Controller also needs the address of the PCI Target along with the number of data words to be transmitted. In the current data storage controller implementation, the PCI Bus Address is thirty-two bits wide, although future PCI bus implementations may utilize multiword addressing and/or significantly larger (64 bit & up) address widths. The single thirty-two bit address word is written by the DSP to memory location aaaa+0×10 in the PCI Control Register Space.

Finally, the PCI Bus Data Write transaction is initiated by writing the PCI Data FIFO word count to a prespecified memory address. The word count value is always decimal 64 or less (0×3F). When the count register is written the value is automatically transferred to the PCI Controller for executing the PCI Bus Master writes.

When the PCI Bus has completed the transfer of all data words within the PCI Data FIFO the PCI Data FIFO Available Interrupt is set. The DSP PCI Data FIFO Available Interrupt handler will then check to see if additional data is waiting or expected to be written to the PCI Data Bus. If additional data is required the interrupt is cleared and the data transfer process repeats. If no additional data is required to be transferred then the interrupt is cleared and the routine must exit to a system state controller. For example, if the command is complete then master mode must be disabled and then slave mode (command mode) enabled—assuming a single command by command execution data storage controller.

For data to be read by the data storage controller from the Host Computer, the DSP must command the PCI Bus with the address and quantity of data to be received.

The PCI Data FIFO is commanded to PCI Bus Data Read Mode by writing to a desired location within the Xilinx (CE3) PCI Control Register Space. Upon PCI Bus Reset the default state for the PCI Data FIFO is Write Mode and the PCI Data FIFO Full Interrupt is cleared. The PCI Data FIFO Full Interrupt should also be cleared via software by writing to such location. The PCI Bus Reset also initializes the PCI Data FIFO Pointer to the first data word of the available 64 data words within the FIFO. However this pointer should always be explicitly initialized by a memory write to prespecified location.

For data to be read from the PCI Bus by the data storage controller, the Xilinx PCI Bus Controller requires the address of the PCI Target along with the number of data words to be received. In the current data storage controller implementation, the PCI Bus Address is thirty-two bits wide, although future PCI bus implementations may utilize multiword addressing and/or significantly larger (64 bit & up) address widths. The single thirty-two bit address word is written by the DSP to prespecified memory location in the PCI Control Register Space.

Finally, the PCI Bus Data Read transaction is initiated by writing the PCI Data FIFO word count to prespecified memory address. The word count value is always decimal 64 or less (0×3F). When the count register is written the value is automatically transferred to the PCI Controller for executing the PCI Bus Master Read.

When the PCI Bus has received all the requested data words PCI Data FIFO Full Interrupt is set. The DSP PCI Data FIFO Full Interrupt handler will then check to see if additional data is waiting or expected to be read from the PCI Data Bus. If additional data is required the interrupt is cleared and the data receipt process repeats. If no additional data is required to be transferred, then the interrupt is cleared and the routine exits to a system state controller. For example, if the command is complete then master mode must be disabled and then slave mode (command mode) enabled—assuming a single command by command execution data storage controller.

It is clearly understood that there are other techniques for handling the PCI Data transfers. The current methodology has been selected to minimize the complexity and resource utilization of the Xilinx Gate Array. It should also be understood that the utilization of asynchronous memory reads and writes to initialize system states and synchronize events at a software level aids in both hardware and system level debug at the expense of increase software overhead. Subsequent embodiments of the gate array may automate resource intensive tasks if system level performance mandates.

IV. Memory Bandwidth Allocation

The onboard cache of the data storage controller is shared by the DSP, Disk Interface, and PCI Bus. The best case, maximum bandwidth for the SDRAM memory is 70 megawords per second, or equivalently, 280 megabytes per second. The 32 bit PCI Bus interface has a best case bandwidth of 132 megabytes per second, or equivalently 33 megawords per second. In current practice, this bandwidth is only achieved in short bursts. The granularity of PCI data bursts to/from the data storage controller is governed by the PCI Bus interface data buffer depth of sixteen words (64 bytes). The time division multiplexing nature of the current PCI Data Transfer Buffering methodology cuts the sustained PCI bandwidth down to 66 megabytes/second.

Data is transferred across the ultraDMA disk interface at a maximum burst rate of 66 megabytes/second. It should be noted that the burst rate is only achieved with disks that contain onboard cache memory. Currently this is becoming more and more popular within the industry. However assuming a disk cache miss, the maximum transfer rates from current disk drives is approximately six megabytes per second. Allotting for technology improvements over time, the data storage controller has been designed for a maximum sustained disk data rate of 20 megabytes second (5 megawords/second). A design challenge is created by the need for continuous access to the SDRAM memory. Disks are physical devices and it is necessary to continuously read data from disk and place it into memory, otherwise the disk will incur a full rotational latency prior to continuing the read transaction. The maximum SDRAM access latency that can be incurred is the depth of the each of the two disk FIFO s or sixteen data. Assuming the FIFO is sixteen words deep the maximum latency time for emptying the other disk FIFO and restoring it to the disk interface is sixteen words at 5 megawords per second or (16×3.2 usec)=1 usec. Each EMIF clock cycle is 14.2857 nsec, thus the maximum latency translates to 224 clock cycles. It should be noted that transfers across the disk interface are 16 bits wide, thus the FPGA is required to translate 32 bit memory transfers to 16 bit disk transfers, and vice-versa.

The DSP services request for its external bus from two requesters, the Enhanced Direct Memory Access (EDMA) Controller and an external shared memory device controller. The DSP can typically utilize the full 280 megabytes of bus bandwidth on an 8k through 64K byte (2k word through 16k word) burst basis. It should be noted that the DSRA does not utilize the SDRAM memory for interim processing storage, and as such only utilizes bandwidth in direct proportion to disk read and write commands.

For a single read from disk transaction data is transferred from and DMA transfer into SDRAM memory. This data is then DMA transferred by the DSP into onboard DSP memory, processed, and re transferred back to SDRAM in decompressed format (3 words for every one word in). Finally the data is read from SDRAM by the PCI Bus Controller and placed into host computer memory. This equates to eight SDRAM accesses, one write from disk, one read by the DSP, three writes by the DSP and three by the PCI Bus. Disk write transactions similarly require eight SDRAM accesses, three from the PCI, three DSP reads, one DSP write, and one to the disk.

Neglecting overhead for setting up DMA transfers, arbitration latencies, and memory wait states for setting up SDRAM transactions, the maximum DSRA theoretical SDRAM bandwidth limit for disk reads or writes is 280/8 megabytes second or 35 megabytes second. It should be noted that the best case allocation of SDRAM bandwidth would be dynamic dependent upon the data compression and decompression ratios. Future enhancements to the data storage controller will utilize a programmable timeslice system to allocate SDRAM bandwidth, however this first embodiment will utilize a fixed allocation ratio as follows:

If all three requestors require SDRAM simultaneously:

PCI Bus Interface 3/8
DSP Accesses 4/8
UltraDMA Disk Interface 1/8

If only the PCI Bus and DSP require SDRAM:

PCI Bus Interface 4/8
DSP Accesses 4/8

If only the DSP and Disk require SDRAM:

DSP Accesses 6/8
UltraDMA Disk Interface 2/8

If only the PCI Bus and Disk require SDRAM:

PCI Bus Interface 6/8
UltraDMA Disk Interface 2/8

If only one device requires SDRAM it receives the full SDRAM bandwidth. It should be noted that different ratios may be applied based upon the anticipated or actual compression and/or decompression ratios. For example in the case of all three requestors active the following equation applies. Assume that data storage accelerator achieves a compression ratio A:B for example 3:1. The Numerator and denominators of the various allocations are defined as follows:

PCI Bus Interface A/K
DSP Accesses (A + B)/K
UltraDMA Disk Interface B/K

Where Further define a sum K equal to the sum of the numerators of the PCI Bus interface fraction, the DSP Access fraction, and the UltraDMA Disk Interfaces, i.e. K=2(A+B). Similarly:

If only the PCI Bus and DSP require SDRAM:

PCI Bus Interface (A + B)/K
DSP Accesses (A + B)/K

If only the DSP and Disk require SDRAM:

DSP Accesses 2A/K
UltraDMA Disk Interface 2B/K

If only the PCI Bus and Disk require SDRAM:

PCI Bus Interface 2A/K
UltraDMA Disk Interface 2B/K

It should be noted that the resultant ratios may all be scaled by a constant in order to most effectively utilize the bandwidths of the internal busses and external interfaces. In addition each ratio can be scale by an adjustment factor based upon the time required to complete individual cycles. For example if PCI Bus interface takes 20% longer than all other cycles, the PCI time slice should be adjusted longer accordingly.
V. Instant Boot Device for Operating System, Application Program and Loading

Typically, with conventional boot device controllers, after reset, the boot device controller will wait for a command over the computer bus (such as PCI). Since the boot device controller will typically be reset prior to bus reset and before the computer bus starts sending commands, this wait period is unproductive time. The initial bus commands inevitably instruct the boot device controller to retrieve data from the boot device (such as a disk) for the operating system. Since most boot devices are relatively slow compared to the speed of most computer busses, a long delay is seen by the computer user. This is evident in the time it takes for a typical computer to boot.

It is to be appreciated that a data storage controller (having an architecture as described herein) may employ a technique of data preloading to decrease the computer system boot time. Upon host system power-up or reset, the data storage controller will perform a self-diagnostic and program the programmable logic device (as discussed above) prior to completion of the host system reset (e.g., PCI bus reset) so that the logic device can accept PCI Bus commands after system reset. Further, prior to host system reset, the data storage controller can proceed to pre-load the portions of the computer operating system from the boot device (e.g., hard disk) into the on-board cache memory. The data storage controller preloads the needed sectors of data in the order in which they will be needed. Since the same portions of the operating system must be loaded upon each boot process, it is advantageous for the boot device controller to preload such portions and not wait until it is commanded to load the operating system. Preferably, the data storage controller employs a dedicated IO channel of the DSP (with or without data compression) to pre-load computer operating systems and applications.

Once the data is preloaded, when the computer system bus issues its first read commands to the data storage controller seeking operating system data, the data will already be available in the cache memory of the data storage controller. The data storage controller will then be able to instantly start transmitting the data to the system bus. Before transmission to the bus, if the was stored in compressed format on the boot device, the data will be decompressed. The process of preloading required (compressed) portions of the operating system significantly reduces the computer boot process time.

In addition to preloading operating system data, the data storage controller could also preload other data that the user would likely want to use at startup. An example of this would be a frequently used application such as a word processor and any number of document files.

There are several techniques that may be employed in accordance with the present invention that would allow the data storage controller to know what data to preload from the boot device. One technique utilizes a custom utility program that would allow the user to specify what applications/data should be preloaded.

Another technique (illustrated by the flow diagram of FIGS. 7a and 7b) that may be employed comprises an automatic process that requires no input from the user. With this technique, the data storage controller maintain a list comprising the data associated with the first series of data requests received by the data storage controller by the host system after a power-on/reset. In particular, referring to FIG. 7a, during the computer boot process, the data storage controller will receive requests for the boot data (step 70). In response, the data storage controller will retrieve the requested boot data from the boot device (e.g., hard disk) in the local cache memory (step 71). For each requested data block, the data storage controller will record the requested data block number in a list (step 72). The data storage controller will record the data block number of each data block requested by the host computer during the boot process (repeat steps 70-72). When the boot process is complete (affirmative determination in step 73), the data storage controller will store the data list on the boot device (or other storage device) (step 74).

Then, upon each subsequent power-on/reset (affirmative result in step 75), the data storage controller would retrieve and read the stored list (step 76) and proceed to preload the boot data specified on the list (i.e., the data associated with the expected data requests) into the onboard cache memory (step 77). It is to be understood that the depending on the resources of the given system (e.g., memory, etc.), the preloading process may be completed prior to commencement of the boot process, or continued after the boot process begins (in which case booting and preloading are performed simultaneously).

When the boot process begins (step 78) (i.e., the storage controller is initialized and the system bus reset is deasserted), the data storage controller will receive requests for boot data (step 79). If the host computer issues a request for boot data that is pre-loaded in the local memory of the data storage controller (affirmative result in step 80), the request is immediately serviced using the preloaded boot data (step 81). If the host computer issues a request for boot data that is not preloaded in the local memory of the data storage controller (negative determination in step 80), the controller will retrieve the requested data from the boot device, store the data in the local memory, and then deliver the requested boot data to the computer bus (step 82). In addition, the data storage controller would update the boot data list by recording any changes in the actual data requests as compared to the expected data requests already stored in the list (step 83). Then, upon the next boot sequence, the boot device controller would pre-load that data into the local cache memory along with the other boot data previously on the list.

Further, during the boot process, if no request is made by the host computer for a data block that was pre-loaded into the local memory of the data storage controller (affirmative result in step 84), then the boot data list will be updated by removing the non-requested data block from the list (step 85). Thereafter, upon the next boot sequence, the data storage controller will not pre-load that data into local memory.

VI. Quick Launch for Operating System, Application Program, and Loading

It is to be appreciated that the data storage controller (having an architecture as described herein) may employ a technique of data preloading to decrease the time to load application programs (referred to as “quick launch”). Conventionally, when a user launches an application, the file system reads the first few blocks of the file off the disk, and then the portion of the loaded software will request via the file system what additional data it needs from the disk. For example, a user may open a spreadsheet program, and the program may be configured to always load a company spreadsheet each time the program is started. In addition, the company spreadsheet may require data from other spreadsheet files.

In accordance with the present invention, the data storage controller may be configured to “remember” what data is typically loaded following the launch of the spreadsheet program, for example. The data storage controller may then proceed to preload the company spreadsheet and all the necessary data in the order is which such data is needed. Once this is accomplished, the data storage controller can service read commands using the preloaded data. Before transmission to the bus, if the preloaded data was stored in compressed format, the data will be decompressed. The process of preloading (compressed) program data significantly reduces the time for launching an application.

Preferably, a custom utility program is employed that would allow the user to specify what applications should be made ready for quick launch.

FIGS. 8a and 8b comprise a flow diagram of a quick launch method according to one aspect of the present invention. With this technique, the data storage controller maintains a list comprising the data associated with launching an application. In particular, when an application is first launched, the data storage controller will receive requests for the application data (step 90). In response, the data storage controller will retrieve the requested application data from memory (e.g., hard disk) and store it in the local cache memory (step 91). The data storage controller will record the data block number of each data block requested by the host computer during the launch process (step 92). When the launch process is complete (affirmative determination in step 93), the data storage controller will store the data list in a designated memory location (step 94).

Then, referring to FIG. 8b, upon each subsequent launch of the application (affirmative result in step 95), the data storage controller would retrieve and read the stored list (step 96) and then proceed to preload the application data specified on the list (i.e., the data associated with the expected data requests) into the onboard cache memory (step 97). During the application launch process, the data storage controller will receive requests for application data (step 98). If the host computer issues a request for application data that is pre-loaded in the local memory of the data storage controller (affirmative result in step 99), the request is immediately serviced using the preloaded data (step 100). If the host computer issues a request for application data that is not preloaded in the local memory of the data storage controller (negative result in step 99), the controller will retrieve the requested data from the hard disk memory, store the data in the local memory, and then deliver the requested application data to the computer bus (step 101). In addition, the data storage controller would update the application data list by recording any changes in the actual data requests as compared to the expected data requests already stored in the list (step 102).

Further, during the launch process, if no request is made by the host computer for a data block that was pre-loaded into the local memory of the data storage controller (affirmative result in step 103), then the application data list will be updated by removing the non-requested data block from the list (step 104). Thereafter, upon the next launch sequence for the given application, the data storage controller will not pre-load that data into local memory.

It is to be understood that the quick boot and quick launch methods described above are preferably implemented by a storage controller according to the present invention and may or may not utilize data compression/decompression by the DSP. However, it is to be understood that the quick boot and quick launch methods may be implemented by a separate device, processor, or system, or implemented in software.

VII. Content Independent Data Compression

It is to be understood that any conventional compression/decompression system and method (which comply with the above mentioned constraints) may be employed in the data storage controller for providing accelerated data storage and retrieval in accordance with the present invention. Preferably, the present invention employs the data compression/decompression techniques disclosed in the above-incorporated U.S. Pat. No. 6,195,024.

Referring to FIG. 9, a detailed block diagram illustrates an exemplary data compression system 110 that may be employed herein. Details of this data compression system are provided in U.S. Pat. No. 6,195,024. In this embodiment, the data compression system 110 accepts data blocks from an input data stream and stores the input data block in an input buffer or cache 115. It is to be understood that the system processes the input data stream in data blocks that may range in size from individual bits through complete files or collections of multiple files. Additionally, the input data block size may be fixed or variable. A counter 120 counts or otherwise enumerates the size of input data block in any convenient units including bits, bytes, words, and double words. It should be noted that the input buffer 115 and counter 120 are not required elements of the present invention. The input data buffer 115 may be provided for buffering the input data stream in order to output an uncompressed data stream in the event that, as discussed in further detail below, every encoder fails to achieve a level of compression that exceeds an a priori specified minimum compression ratio threshold.

Data compression is performed by an encoder module 125 which may comprise a set of encoders E1, E2, E3 . . . En. The encoder set E1, E2, E3 . . . En may include any number “n” (where n may=1) of those lossless encoding techniques currently well known within the art such as run length, Huffman, Lempel-Ziv Dictionary Compression, arithmetic coding, data compaction, and data null suppression. It is to be understood that the encoding techniques are selected based upon their ability to effectively encode different types of input data. It is to be appreciated that a full complement of encoders are preferably selected to provide a broad coverage of existing and future data types.

The encoder module 125 successively receives as input each of the buffered input data blocks (or unbuffered input data blocks from the counter module 120). Data compression is performed by the encoder module 125 wherein each of the encoders E1 . . . En processes a given input data block and outputs a corresponding set of encoded data blocks. It is to be appreciated that the system affords a user the option to enable/disable any one or more of the encoders E1 . . . En prior to operation. As is understood by those skilled in the art, such feature allows the user to tailor the operation of the data compression system for specific applications. It is to be further appreciated that the encoding process may be performed either in parallel or sequentially. In particular, the encoders E1 through En of encoder module 125 may operate in parallel (i.e., simultaneously processing a given input data block by utilizing task multiplexing on a single central processor, via dedicated hardware, by executing on a plurality of processor or dedicated hardware systems, or any combination thereof). In addition, encoders E1 through En may operate sequentially on a given unbuffered or buffered input data block. This process is intended to eliminate the complexity and additional processing overhead associated with multiplexing concurrent encoding techniques on a single central processor and/or dedicated hardware, set of central processors and/or dedicated hardware, or any achievable combination. It is to be further appreciated that encoders of the identical type may be applied in parallel to enhance encoding speed. For instance, encoder E1 may comprise two parallel Huffman encoders for parallel processing of an input data block.

A buffer/counter module 130 is operatively connected to the encoder module 125 for buffering and counting the size of each of the encoded data blocks output from encoder module 125. Specifically, the buffer/counter 130 comprises a plurality of buffer/counters BC1, BC2, BC3 . . . BCn, each operatively associated with a corresponding one of the encoders E1 . . . En. A compression ratio module 135, operatively connected to the output buffer/counter 130, determines the compression ratio obtained for each of the enabled encoders E1 . . . En by taking the ratio of the size of the input data block to the size of the output data block stored in the corresponding buffer/counters BC1 . . . BCn. In addition, the compression ratio module 135 compares each compression ratio with an a priori-specified compression ratio threshold limit to determine if at least one of the encoded data blocks output from the enabled encoders E1 . . . En achieves a compression that exceeds an a priori-specified threshold. As is understood by those skilled in the art, the threshold limit may be specified as any value inclusive of data expansion, no data compression or expansion, or any arbitrarily desired compression limit. A description module 138, operatively coupled to the compression ratio module 135, appends a corresponding compression type descriptor to each encoded data block which is selected for output so as to indicate the type of compression format of the encoded data block. A data compression type descriptor is defined as any recognizable data token or descriptor that indicates which data encoding technique has been applied to the data. It is to be understood that, since encoders of the identical type may be applied in parallel to enhance encoding speed (as discussed above), the data compression type descriptor identifies the corresponding encoding technique applied to the encoded data block, not necessarily the specific encoder. The encoded data block having the greatest compression ratio along with its corresponding data compression type descriptor is then output for subsequent data processing, storage, or transmittal. If there are no encoded data blocks having a compression ratio that exceeds the compression ratio threshold limit, then the original unencoded input data block is selected for output and a null data compression type descriptor is appended thereto. A null data compression type descriptor is defined as any recognizable data token or descriptor that indicates no data encoding has been applied to the input data block. Accordingly, the unencoded input data block with its corresponding null data compression type descriptor is then output for subsequent data processing, storage, or transmittal.

Again, it is to be understood that the embodiment of the data compression engine of FIG. 9 is exemplary of a preferred compression system which may be implemented in the present invention, and that other compression systems and methods known to those skilled in the art may be employed for providing accelerated data storage in accordance with the teachings herein. Indeed, in another embodiment of the compression system disclosed in the above-incorporated U.S. Pat. No. 6,195,024, a timer is included to measure the time elapsed during the encoding process against an a priori-specified time limit. When the time limit expires, only the data output from those encoders (in the encoder module 125) that have completed the present encoding cycle are compared to determine the encoded data with the highest compression ratio. The time limit ensures that the real-time or pseudo real-time nature of the data encoding is preserved. In addition, the results from each encoder in the encoder module 125 may be buffered to allow additional encoders to be sequentially applied to the output of the previous encoder, yielding a more optimal lossless data compression ratio. Such techniques are discussed in greater detail in the above-incorporated U.S. Pat. No. 6,195,024.

Referring now to FIG. 10, a detailed block diagram illustrates an exemplary decompression system that may be employed herein or accelerated data retrieval as disclosed in the above-incorporated U.S. Pat. No. 6,195,024. In this embodiment, the data compression engine 180 retrieves or otherwise accepts compressed data blocks from one or more data storage devices and inputs the data via a data storage interface. It is to be understood that the system processes the input data stream in data blocks that may range in size from individual bits through complete files or collections of multiple files. Additionally, the input data block size may be fixed or variable.

The data decompression engine 180 comprises an input buffer 155 that receives as input an uncompressed or compressed data stream comprising one or more data blocks. The data blocks may range in size from individual bits through complete files or collections of multiple files. Additionally, the data block size may be fixed or variable. The input data buffer 55 is preferably included (not required) to provide storage of input data for various hardware implementations. A descriptor extraction module 160 receives the buffered (or unbuffered) input data block and then parses, lexically, syntactically, or otherwise analyzes the input data block using methods known by those skilled in the art to extract the data compression type descriptor associated with the data block. The data compression type descriptor may possess values corresponding to null (no encoding applied), a single applied encoding technique, or multiple encoding techniques applied in a specific or random order (in accordance with the data compression system embodiments and methods discussed above).

A decoder module 165 includes one or more decoders D1 . . . Dn for decoding the input data block using a decoder, set of decoders, or a sequential set of decoders corresponding to the extracted compression type descriptor. The decoders D1 . . . Dn may include those lossless encoding techniques currently well known within the art, including: run length, Huffman, Lempel-Ziv Dictionary Compression, arithmetic coding, data compaction, and data null suppression. Decoding techniques are selected based upon their ability to effectively decode the various different types of encoded input data generated by the data compression systems described above or originating from any other desired source.

As with the data compression systems discussed in U.S. application Ser. No. 09/210,491, the decoder module 165 may include multiple decoders of the same type applied in parallel so as to reduce the data decoding time. An output data buffer or cache 170 may be included for buffering the decoded data block output from the decoder module 165. The output buffer 70 then provides data to the output data stream. It is to be appreciated by those skilled in the art that the data compression system 180 may also include an input data counter and output data counter operatively coupled to the input and output, respectively, of the decoder module 165. In this manner, the compressed and corresponding decompressed data block may be counted to ensure that sufficient decompression is obtained for the input data block.

Again, it is to be understood that the embodiment of the data decompression system 180 of FIG. 10 is exemplary of a preferred decompression system and method which may be implemented in the present invention, and that other data decompression systems and methods known to those skilled in the art may be employed for providing accelerated data retrieval in accordance with the teachings herein.

VIII. Data Acceleration Controller

The block diagrams of FIGS. 11 and 12 illustrate disk architectures according to additional embodiments of the present invention. FIG. 11 and FIG. 12 illustrate composite implementations of disk controller frameworks. Novel aspects of these architectures include, for example, the incorporation of a separate disk controller function and the addition of a data compression/decompression engine.

The benefits of such architectures are numerous, including, for example, increased reliability due to fewer components, higher throughput performance by eliminating unnecessary interfaces and handling less data due to compression, compression will aid in the thirst for greater disk densities, lower overall system costs due to less components and mechanical interfaces, and the ability to implement transparent pipelining to the host for increased system performance.

In general, the disk controller architectures in FIGS. 11 and 12 essentially provide an interface directly from the disk to the host main bus. Any number of busses could be implemented such as PCI, PCMCIA, Pentium, VMEBUS, etc.

The disk controller framework illustrated in FIG. 11 comprises a disk controls and status module 1110, a cache management and interface control module 1120, a data cache 1130, a compression/decompression engine 1140, host interface busses 1150, a local high-speed bus 1160 and a data and command cache 1170. The data and command cache 1170 is operatively connected to the host interface busses 1150 (via a host interface buffered data bus 80) and to the data compression/decompression engine 1140 via the local bus 1160, to thereby allow data to be transferred to/from the host while the compression engine 1140 works on another buffered data block. The architecture of FIG. 11 maximizes pipelining and produces a maximum throughput.

FIG. 12 is a block diagram of a disk controller according to another embodiment of the present invention, comprising a disk controls and status module 1110, a cache management and interface control module 1120, a data cache 1130, a compression/decompression engine 1140, host interface busses 1150, and a local high-speed bus 1160. The architecture of FIG. 12 comprises a single buffer between the host and the compression engine 1140 and comprises a more cost effective architecture than that of FIG. 11, but with reduced throughput in certain applications.

In the frameworks of FIGS. 11 and 12, the data cache 1130 is connected to the data compression/decompression engine 1140 and the actual disk, which enable overlap of disk operations with data storage operations. The local high-speed bus 1160 in both architectures preferably operates primarily in block mode for optimal efficiency. The cache management & interface control module 1120, which communicates with the compression engine 1140 over a dedicated secondary high-speed bus 1190, controls the data flow through the disk system under commands from the compression/decompression engine 1140. This architecture allows data to flow from the disk and the host interface at the same time while the engine 1140 is operating on a separate block of data.

In a preferred embodiment of the present invention, the data compression/decompression engine 1140 employs the compression/decompression methods described in the above-incorporated U.S. Pat. No. 6,195,024, issued Feb. 27, 2001 to J. Fallon, U.S. Pat. No. 6,309,424, issued on Oct. 30, 2001 to J. Fallon, and/or the techniques described in U.S. patent application Ser. No. 10/016,355, filed on Oct. 29, 2001, which are all commonly assigned and incorporated herein by reference. It should be noted in the following discussion that the use of the term DSP (digital signal processor) may also refer to a plurality of DSP(s), one or a plurality of general purpose processors, finite state machines, micro code, logic, firmware, or software.

The data compression and decompression functions to accomplish data storewidth acceleration and or storage multiplication may be accomplished in either hardware, software, or any combination thereof.

In accordance with the present invention, minimizing the cost of the data storage and maximizing retrieval storewidth acceleration and or storage multiplication function is preferably achieved by sharing hardware and or software resources.

VIII. Data Accelerator Embedded in Disk and Other Data Storage Devices

FIG. 13 is a block diagram of a magnetic disk controller according to another embodiment of the present invention. It should be noted that although the exemplary embodiment of FIG. 13 describes a magnetic disk, the present invention is applicable to any mass storage device. A magnetic disk implementation according to an embodiment of the present invention comprises a host computer interface 1300 coupled to a compression/decompression engine 1301, a bi-directional cache 1302, a command and status control module 1303, a cache management/virtual file system 1304 and/or full host file system. The system further comprises high performance Giant Magneto Resistive Heads 1305, analog signal processing/data recognition module 1306, a decoding and tracking module 1307, a closed loop positioning module 1308, multistage linear actuators 1309 for positioning, ramp load/unloading of heads, closed loop brushless DC motors 1310 with liquid bearings and associated drivers 1311, and a power conversion and management system 1312. Additional functions (not shown) comprise dynamic head calibrations, static head calibrations, dynamic calibration functions, static calibration functions, and corrections for time, temperature, aging, stress, and radiation, along with error detection and correction functions.

In one embodiment of the present invention, a DSP is utilized for storewidth acceleration and or storage multiplication, as well as other disk functions or control thereof as mentioned above. For example, in one embodiment, the virtual file management system 1304 and/or cache system 1302 are implemented in the same DSP. In another embodiment, management of a bi-directional cache, separate read/write caches, and or compressed/uncompressed caches, or any combination thereof, is also managed by the DSP. In another embodiment of the present invention, the disk command and control functions are further implemented in the DSP.

In another embodiment of the present invention, one or more of the following functions may be advantageously implemented in the DSP: data recognition or correlation, decoding and tracking, closed loop servo positioning, multistage linear actuator control for positioning, ramp load/unload management and control, closed loop brushless DC motor control, liquid bearing monitoring (temperature, fluid level), and power conversion and management system.

Additional functions comprise on the fly dynamic head calibrations with read/write testing, or with pre-stored patterns on the disk, static head calibrations (performed at construction or periodically), dynamic and static calibration functions performed periodically or by command, along with corrections for time, temperature, aging, stress, radiation, along with canonical error detection and correction functions.

Accordingly, it is to be appreciated that either all the functions or any portion thereof might be implemented in the DSP, with the balance by any available means including dedicated logic, other processors, finite state machines, micro code, firmware, or software.

In yet another embodiment of the present invention, the virtual file management system 1304 may be executed in an alternate processor, for example in the host computer, to offload the DSP or other disk processing for other data acceleration, bandwidth multiplication, and aforementioned disk functions. The virtual file management system 1304 is utilized to map uncompressed/unaccelerated blocks to the disk when they are compressed. With the present invention, a compressed data block occupies the same or less space than the original data. As such, the file management system 1304 must be aware of the new data size in order to store data efficiently on the disk. Current storage methods for disks, along with most other mass storage devices, store data in blocks that are either fixed or variable in size. The virtual file management 1304 system allows the appropriate data to be stored or retrieved even when the actual data is different in size than the original uncompressed data. Embedding the virtual file management system 1304 within the mass storage device has the advantage of reducing costs by sharing the processing and virtual file management mapping tasks. Virtual file management and data block mapping may be accomplished via look up tables or mathematical hashing functions. The mapping or hashing function virtualizes the physical disk or mass storage space. Assuming a 3:1 compression ratio, a one terabyte physical disk appears as a three terabyte virtual disk. The virtual file system 1304 allows uncompressed data in the three terabyte virtual space to be stored efficiently in the one terabyte physical space. Mapping data in small blocks has the advantage of being able to store, retrieve, or append with smaller more efficient units of data at the expense of larger look-up tables or more complex hashing functions.

In another embodiment of the present invention cache management is employed to manage data caching in both the physical space to the virtual space. Data retrieved from the mass storage device is stored compressed in a cache awaiting a cache hit. Typically, when data is retrieved, physically adjacent data or data known to be frequently referenced within the context of the retrieved data is also read from disk. Caches are typically uncompressed and thus require more memory and additional bandwidth for transfer. By caching compressed data on data reads, the cache is capable of storing a significantly larger quantity of data, making the likelihood of cache hits better and thus increasing system performance. Data is then decompressed when called for or in the background when the disk or controller is idle.

For data writes, the compressed data is stored in the cache awaiting synchronization with the mass storage disk or memory device. Again, the cache is capable of storing a much larger quantity of data (a function of compression ratio) and thus increases overall system performance.

In other embodiments, any element of the above-mentioned disk functions may be implemented wholly or partially with the disk DSP(s), host processor(s), alternate processor(s), or any combination thereof.

In yet another embodiment, the virtual file management system and the host operating system file management system are merged, with the results of the compression/decompression process utilized to minimize redundant disk management tasks. This function may be resident within the disk, within the host(s), or any combination thereof. The virtual file management system can consume significant processing resources, as such it may not always be optimal to embed the virtual file system within the mass storage device. The processing can be resident in the host, thus allowing the disk processor to work on disk management and data acceleration tasks, split between the two, or wholly resident within the storage device.

In yet another embodiment of the present invention the data acceleration is performed solely with the host. For example in Network Attached Storage Services and other mass storage arrays it may be advantageous to have the data acceleration solely within one or more host CPUs. The CPU(s) can share workload with other functions, such as network interfacing and application processing. The virtual file system can also be allocated to one or more of the same CPUs or it can be performed within the mass storage or disk device.

In another embodiment of the present invention, the DSP utilized for the data storewidth acceleration or storage multiplication is also utilized to perform the monitoring and actuation functions for a bearing fluid replenishment system as described below. The monitoring and actuation functions for the bearing fluid replenishment system may be performed in a separate processor, DSP, one or a plurality of general purpose processors, finite state machines, micro code, logic, firmware, or software—in addition the control function may be implemented in the host computer.

A bearing fluid replenishment system according to one embodiment of the present invention is utilized with a bearing fluid reservoir to extend the life of the bearing system. An actuator is utilized to fill the fluid to a constant level. Further the fluid level or pressure within the system is maintained at a constant level. For example, in the case of fluid dynamic bearings, the pressure is preferably maintained a constant level to provide minimum frictional losses while still isolating the rotating parts from contact. In another aspect of the present invention, the pressure and or fluid level is adjusted to optimum as a function of spin rate. In yet another aspect of the present invention, the fluid level or pressure is adjusted to optimum as a function of temperature. In yet another aspect of the present invention, the fluid level and/or pressure is adjusted according to closed loop feedback from the motor current or power consumption to an optimal level. In yet another aspect of the present invention, any combination of the above parameters are utilized in optimal combination to achieve lowest wear, longest life, highest reliability, minimum breakaway friction, minimum frictional losses, lowest power consumption, etc.

Moving fluid from the reservoir to the bearing chamber and/or back is accomplished by any means including piezo actuators, expandable/compressible diaphragms, mechanical actuators, electromagnetic actuators, gas pressure by heat, or any other means.

Although illustrative embodiments have been described herein with reference to the accompanying drawings, it is to be understood that the present invention is not limited to those precise embodiments, and that various other changes and modifications may be affected therein by one skilled in the art without departing from the scope or spirit of the invention. All such changes and modifications are intended to be included within the scope of the invention as defined by the appended claims.

Fallon, James J.

Patent Priority Assignee Title
10015143, Jun 05 2014 F5 Networks, Inc Methods for securing one or more license entitlement grants and devices thereof
10019458, Mar 11 1999 Realtime Data LLC System and methods for accelerated data storage and retrieval
10033405, Dec 11 1998 Realtime Data LLC Data compression systems and method
10033837, Sep 29 2012 F5 Networks, Inc System and method for utilizing a data reducing module for dictionary compression of encoded data
10045018, Feb 13 2001 Realtime Adaptive Streaming LLC Asymmetric data decompression systems
10135831, Jan 28 2011 F5 Networks, Inc. System and method for combining an access control system with a traffic management system
10182013, Dec 01 2014 F5 Networks, Inc Methods for managing progressive image delivery and devices thereof
10212417, Feb 13 2001 Realtime Adaptive Streaming LLC Asymmetric data decompression systems
10242405, Nov 05 2003 Chicago Mercantile Exchange Inc. Trade engine processing of mass quote messages and resulting production of market data
10284225, Oct 03 2000 Realtime Data, LLC Systems and methods for data compression
10304133, Nov 05 2003 Chicago Mercantile Exchange Inc. Distribution of market data
10346043, Dec 28 2015 Pure Storage, Inc.; Pure Storage, Inc Adaptive computing for data compression
10375155, Feb 19 2013 F5 Networks, Inc. System and method for achieving hardware acceleration for asymmetric flow connections
10419021, Oct 03 2000 Realtime Data, LLC Systems and methods of data compression
10587284, Apr 09 2018 International Business Machines Corporation Multi-mode compression acceleration
10587287, Mar 28 2018 International Business Machines Corporation Computer system supporting multiple encodings with static data support
10720941, Apr 09 2018 International Business Machines Corporation Computer system supporting migration between hardware accelerators through software interfaces
10732837, Feb 08 2010 International Business Machines Corporation Pseudo-volume for control and statistics of a storage controller
10903852, Mar 28 2018 International Business Machines Corporation Computer system supporting multiple encodings with static data support
10972453, May 03 2017 F5 Networks, Inc. Methods for token refreshment based on single sign-on (SSO) for federated identity environments and devices thereof
10991043, Nov 05 2003 Chicago Mercantile Exchange Inc. Distribution of market data
11005496, Apr 09 2018 International Business Machines Corporation Multi-mode compression acceleration
11164248, Oct 12 2015 Chicago Mercantile Exchange Inc. Multi-modal trade execution with smart order routing
11281375, Dec 28 2015 Pure Storage, Inc. Optimizing for data reduction in a storage system
11288739, Oct 12 2015 Chicago Mercantile Exchange Inc.; CHICAGO MERCANTILE EXCHANGE INC Central limit order book automatic triangulation system
11537716, Nov 13 2018 F5, INC Methods for detecting changes to a firmware and devices thereof
11823267, Oct 12 2015 Chicago Mercantile Exchange Inc. Central limit order book automatic triangulation system
11838851, Jul 15 2014 F5 Networks, Inc Methods for managing L7 traffic classification and devices thereof
11855898, Mar 14 2018 F5 Networks, Inc Methods for traffic dependent direct memory access optimization and devices thereof
11861703, Oct 12 2015 Chicago Mercantile Exchange Inc. Multi-modal trade execution with smart order routing
11895138, Feb 02 2015 F5 Networks, Inc Methods for improving web scanner accuracy and devices thereof
7714747, Dec 11 1998 Realtime Data LLC Data compression systems and methods
7739440, Aug 16 2007 Texas Instruments Incorporated; Texas Instruments Inc ATA HDD interface for personal media player with increased data transfer throughput
7777651, Oct 03 2000 Realtime Data LLC System and method for data feed acceleration and encryption
7831491, Nov 05 2003 CHICAGO MERCANTILE EXCHANGE, INC Market data message format
7844766, Oct 03 2008 WINDSTREAM SERVICES, LLC System and method for location specific computer enabled services/monitoring
8054879, Feb 13 2001 Realtime Adaptive Streaming LLC Bandwidth sensitive data compression and decompression
8073047, Feb 13 2001 Realtime Adaptive Streaming LLC Bandwidth sensitive data compression and decompression
8090936, Feb 03 2000 Realtime Data, LLC Systems and methods for accelerated loading of operating systems and application programs
8095711, Jul 02 2007 CORIANT OY Method and devices for compressing delta log using flash transactions
8103809, Jan 16 2009 F5 Networks, Inc Network devices with multiple direct memory access channels and methods thereof
8112491, Jan 16 2009 F5 Networks, Inc.; F5 Networks, Inc Methods and systems for providing direct DMA
8112619, Feb 03 2000 Realtime Data LLC Systems and methods for accelerated loading of operating systems and application programs
8229820, Nov 05 2003 Chicago Mercantile Exchange Inc. Market data message format
8275897, Mar 11 1999 Realtime Data, LLC System and methods for accelerated data storage and retrieval
8306036, Jun 20 2008 F5 Networks, Inc. Methods and systems for hierarchical resource allocation through bookmark allocation
8341056, Nov 05 2003 Chicago Mercantile Exchange Inc. Distribution of market data
8364836, Mar 11 1999 Realtime Data LLC System and methods for accelerated data storage and retrieval
8447884, Dec 01 2008 F5 Networks, Inc. Methods for mapping virtual addresses to physical addresses in a network device and systems thereof
8502707, Dec 11 1998 Realtime Data, LLC Data compression systems and methods
8504710, Mar 11 1999 Realtime Data LLC System and methods for accelerated data storage and retrieval
8537825, Sep 28 2007 F5 Networks, Inc. Lockless atomic table update
8553759, Feb 13 2001 Realtime Adaptive Streaming LLC Bandwidth sensitive data compression and decompression
8560443, Nov 05 2003 Chicago Mercantile Exchange, Inc. Distribution of market data
8626625, Nov 05 2003 Chicago Mercantile Exchange Inc. Trade engine processing of mass quote messages and resulting production of market data
8643513, Dec 11 1998 Realtime Data LLC Data compression systems and methods
8692695, Oct 03 2000 Realtime Data, LLC Methods for encoding and decoding data
8717203, Dec 11 1998 Realtime Data, LLC Data compression systems and methods
8717204, Oct 03 2000 Realtime Data LLC Methods for encoding and decoding data
8719438, Mar 11 1999 Realtime Data LLC System and methods for accelerated data storage and retrieval
8723701, Oct 03 2000 Realtime Data LLC Methods for encoding and decoding data
8742958, Oct 03 2000 Realtime Data LLC Methods for encoding and decoding data
8756332, Mar 11 1999 Realtime Data LLC System and methods for accelerated data storage and retrieval
8769681, Aug 11 2008 F5 Networks, Inc. Methods and system for DMA based distributed denial of service protection
8867610, Feb 13 2001 Realtime Adaptive Streaming LLC System and methods for video and audio data distribution
8880632, Jan 16 2009 F5 Networks, Inc Method and apparatus for performing multiple DMA channel based network quality of service
8880696, Jan 16 2009 F5 Networks, Inc Methods for sharing bandwidth across a packetized bus and systems thereof
8880862, Feb 03 2000 Realtime Data, LLC Systems and methods for accelerated loading of operating systems and application programs
8897356, Feb 13 2001 Realtime Data LLC Systems and methods for video and audio data storage and distribution
8929442, Feb 13 2001 Realtime Adaptive Streaming LLC System and methods for video and audio data distribution
8933825, Dec 11 1998 Realtime Data LLC Data compression systems and methods
8934535, Feb 13 2001 Realtime Adaptive Streaming LLC Systems and methods for video and audio data storage and distribution
8984178, Jan 16 2009 F5 Networks, Inc. Network devices with multiple direct memory access channels and methods thereof
9036822, Feb 15 2012 F5 Networks, Inc. Methods for managing user information and devices thereof
9054728, Dec 11 1998 Realtime Data, LLC Data compression systems and methods
9116908, Mar 11 1999 Realtime Data LLC System and methods for accelerated data storage and retrieval
9141992, Oct 03 2000 Realtime Data LLC Data feed acceleration
9143546, Oct 03 2000 Realtime Data LLC System and method for data feed acceleration and encryption
9152483, Jan 16 2009 F5 Networks, Inc Network devices with multiple fully isolated and independently resettable direct memory access channels and methods thereof
9154453, Jan 16 2009 F5 Networks, Inc. Methods and systems for providing direct DMA
9236882, Dec 11 1998 Realtime Data, LLC Data compression systems and methods
9270602, Dec 31 2012 F5 Networks, Inc Transmit rate pacing of large network traffic bursts to reduce jitter, buffer overrun, wasted bandwidth, and retransmissions
9313047, Nov 06 2009 F5 Networks, Inc. Handling high throughput and low latency network data packets in a traffic management device
9560357, Feb 13 2001 Realtime Data LLC System and methods for video and audio data distribution
9571123, Dec 11 1998 Realtime Data, LLC Data compression systems and methods
9606946, Jan 16 2009 F5 Networks, Inc. Methods for sharing bandwidth across a packetized bus and systems thereof
9635024, Dec 16 2013 F5 Networks, Inc Methods for facilitating improved user authentication using persistent data and devices thereof
9659330, Nov 05 2003 Chicago Mercantile Exchange, Inc. Distribution of market data
9667751, Oct 03 2000 Realtime Data, LLC Data feed acceleration
9762907, Feb 13 2001 Realtime Adaptive Streaming LLC System and methods for video and audio data distribution
9769477, Feb 13 2001 Realtime Adaptive Streaming LLC Video data compression systems
9792128, Feb 03 2000 Realtime Data, LLC System and method for electrical boot-device-reset signals
9859919, Oct 03 2000 Realtime Data LLC System and method for data compression
9864606, Sep 05 2013 F5 Networks, Inc Methods for configurable hardware logic device reloading and devices thereof
9967368, Oct 03 2000 Realtime Data LLC Systems and methods for data block decompression
Patent Priority Assignee Title
4302775, Dec 15 1978 MAGNITUDE COMPRESSION SYSTEMS, INC Digital video compression system and methods utilizing scene adaptive coding with rate buffer feedback
4394774, Dec 15 1978 MAGNITUDE COMPRESSION SYSTEMS, INC Digital video compression system and methods utilizing scene adaptive coding with rate buffer feedback
4574351, Mar 03 1983 International Business Machines Corporation Apparatus for compressing and buffering data
4593324, Apr 14 1981 Fuji Xerox Co., Ltd. Image data storing device
4682150, Dec 09 1985 TELEDATA SOUND LLC Data compression method and apparatus
4730348, Sep 19 1986 Adaptive Computer Technologies Adaptive data compression system
4804959, Nov 10 1987 International Business Machines Corporation Method and apparatus using multiple codes to increase storage capacity
4870415, Oct 19 1987 Hewlett-Packard Company Data compression system with expansion protection
4872009, Dec 12 1986 Hitachi, Ltd.; Hitachi Computer Peripherals Co. Method and apparatus for data compression and restoration
4876541, Oct 15 1987 STORER, JAMES A Stem for dynamically compressing and decompressing electronic data
4888812, Dec 18 1987 INTERNATIONAL BUSINESS MACHINES CORPORATION, A CORP OF NY Document image processing system
4906995, Dec 12 1986 Sangamo Weston, Inc. Data compression apparatus and method for data recorder
4929946, Feb 09 1989 Storage Technology Corporation Adaptive data compression apparatus including run length encoding for a tape drive system
4965675, May 15 1987 Canon Kabushiki Kaisha Method and apparatus for after-recording sound on a medium having pre-recorded video thereon
4988998, Sep 05 1989 Storage Technology Corporation Data compression system for successively applying at least two data compression methods to an input data stream
5028922, Oct 30 1989 Industrial Technology Research Institute Multiplexed encoder and decoder with address mark generation/check and precompensation circuits
5045848, Apr 10 1984 Data Broadcasting Corporation Method of encoding market data and transmitting by radio to a plurality of receivers
5045852, Mar 30 1990 International Business Machines Corporation Dynamic model selection during data compression
5046027, Nov 08 1988 Massachusetts General Hospital Apparatus and method for processing and displaying images in a digital procesor based system
5049881, Jun 18 1990 Intersecting Concepts, Inc. Apparatus and method for very high data rate-compression incorporating lossless data compression and expansion utilizing a hashing technique
5091782, Apr 09 1990 CIF LICENSING, LLC Apparatus and method for adaptively compressing successive blocks of digital video
5097261, Nov 22 1989 International Business Machines Corporation Data compression for recording on a record medium
5113522, May 17 1989 International Business Machines Corporation Data processing system with system resource management for itself and for an associated alien processor
5121342, Aug 28 1989 Network Communications Corporation Apparatus for analyzing communication networks
5150430, Mar 15 1991 The Board of Trustees of the Leland Stanford Junior University Lossless data compression circuit and method
5159336, Aug 13 1991 DITTO, INC Tape controller with data compression and error correction sharing a common buffer
5175543, Sep 25 1991 Hewlett-Packard Company Dictionary reset performance enhancement for data compression applications
5179651, Nov 08 1988 Massachusetts General Hospital Apparatus for retrieval and processing of selected archived images for display at workstation terminals
5187793, Jan 09 1989 Intel Corporation Processor with hierarchal memory and using meta-instructions for software control of loading, unloading and execution of machine instructions stored in the cache
5191431, Aug 29 1989 Canon Kabushiki Kaisha Recording apparatus having plural operating modes involving diverse signal compression rates and different apportioning of pilot signal recording area
5204756, Aug 04 1989 IPG HEALTHCARE 501 LIMITED Method for high-quality compression of binary text images
5209220, Oct 05 1989 Olympus Optical Co., Ltd. Endoscope image data compressing apparatus
5212742, May 24 1991 Apple Inc Method and apparatus for encoding/decoding image data
5226176, Aug 20 1990 Microsystems, Inc. System for selectively aborting operation or waiting to load required data based upon user response to non-availability of network load device
5227893, Oct 31 1990 International Business Machines Corporation; INTERNATIONAL BUSINESS MACHINES CORPORATION, A CORP OF NEW YORK Pseudo-bar code control of image transmission
5231492, Mar 16 1989 Fujitsu Limited Video and audio multiplex transmission system
5237460, Dec 14 1990 DIGITAL DATA FUNDING LLC Storage of compressed data on random access storage devices
5237675, Jun 04 1990 MAXTOR CORP Apparatus and method for efficient organization of compressed data on a hard disk utilizing an estimated compression factor
5243341, Jun 01 1992 Hewlett-Packard Company Lempel-Ziv compression scheme with enhanced adapation
5243348, Apr 27 1992 Freescale Semiconductor, Inc Partitioned digital encoder and method for encoding bit groups in parallel
5247638, Jun 18 1990 Storage Technology Corporation Apparatus for compressing data in a dynamically mapped virtual data storage subsystem
5247646, May 15 1986 COMPUTER UPGRADE CORPORATION Compressed data optical disk storage system
5263168, Jun 03 1991 Freescale Semiconductor, Inc Circuitry for automatically entering and terminating an initialization mode in a data processing system in response to a control signal
5270832, Mar 14 1990 LSI Logic Corporation System for compression and decompression of video data using discrete cosine transform and coding techniques
5287420, Apr 08 1992 AUTODESK, Inc Method for image compression on a personal computer
5293379, Apr 22 1991 Mitel Corporation Packet-based data compression method
5307497, Jun 25 1990 LENOVO SINGAPORE PTE LTD Disk operating system loadable from read only memory using installable file system interface
5309555, May 15 1990 International Business Machines Corporation Realtime communication of hand drawn images in a multiprogramming window environment
5355498, Feb 25 1992 Sun Microsystems, Inc. Method and apparatus for booting a computer system without loading a device driver into memory
5357614, Sep 17 1992 TECMAR TECHNOLOGIES, INC Data compression controller
5379036, Apr 01 1992 Method and apparatus for data compression
5379757, Aug 28 1990 Olympus Optical Co. Ltd. Method of compressing endoscope image data based on image characteristics
5381145, Feb 10 1993 Ricoh Company, LTD Method and apparatus for parallel decoding and encoding of data
5394534, Sep 11 1992 MEDIATEK INC Data compression/decompression and storage of compressed and uncompressed data on a same removable data storage medium
5396228, Jan 16 1992 SKYTEL CORP Methods and apparatus for compressing and decompressing paging data
5400401, Oct 30 1992 TECH 5 SAS System and method for transmitting a plurality of digital services
5403639, Sep 02 1992 Storage Technology Corporation File server having snapshot application data groups
5406278, Feb 28 1992 INTERSECTING CONCEPTS, INC Method and apparatus for data compression having an improved matching algorithm which utilizes a parallel hashing technique
5406279, Sep 02 1992 Cirrus Logic, INC General purpose, hash-based technique for single-pass lossless data compression
5412384, Apr 16 1993 International Business Machines Corporation Method and system for adaptively building a static Ziv-Lempel dictionary for database compression
5414850, Aug 23 1991 HI FN, INC System for transparently compressing data files in a computer system
5420639, Apr 01 1993 Cisco Technology, Inc Rate adaptive huffman coding
5434983, Aug 30 1991 Matsushita Graphic Communication Systems Data processing apparatus having first bus with bus arbitration independent of CPU, second bus for CPU, and gate between first and second buses
5452287, Sep 20 1993 Motorola Mobility LLC Method of negotiation of protocols, classes, and options in computer and communication networks providing mixed packet, frame, cell, and circuit services
5461679, May 24 1991 Apple Inc Method and apparatus for encoding/decoding image data
5467087, Dec 18 1992 Apple Inc High speed lossless data compression system
5471206, Feb 10 1993 Ricoh Company Ltd Method and apparatus for parallel decoding and encoding of data
5479587, Sep 03 1992 Hewlett-Packard Company Page printer having adaptive data compression for memory minimization
5483470, Mar 06 1990 Alcatel Lucent Timing verification by successive approximation
5486826, May 19 1994 USATALKS COM, INC Method and apparatus for iterative compression of digital data
5495244, Dec 07 1991 Samsung Electronics Co., Ltd. Device for encoding and decoding transmission signals through adaptive selection of transforming methods
5506844, May 20 1994 Google Technology Holdings LLC Method for configuring a statistical multiplexer to dynamically allocate communication channel bandwidth
5506872, Apr 26 1994 AVAYA Inc Dynamic compression-rate selection arrangement
5530845, May 13 1992 SBC Technology Resources, INC Storage control subsystem implemented with an application program on a computer
5533051, Mar 12 1993 HYPERSPACE COMMUNICATIONS, INC Method for data compression
5535356, Sep 09 1991 Samsung Electronics Co., Ltd. Digital data recording/playback system utilizing EEPROM and ROM memories as a storage medium
5537658, Jun 07 1995 HGST NETHERLANDS B V Distributed directory method and structure for direct access storage device (DASD) data compression
5557551, Oct 27 1993 International Business Machines Corporation Method and apparatus for a thermal protection unit
5557668, Jun 25 1992 TELEDATA SOLUTIONS, INC Call distribution system with distributed control of calls and data distribution
5557749, Oct 15 1992 Micron Technology, Inc System for automatically compressing and decompressing data for sender and receiver processes upon determination of a common compression/decompression method understood by both sender and receiver processes
5561824, Oct 04 1994 International Business Machines Corporation Storage management of data for ensuring communication of minimal length data
5563961, Mar 03 1994 AUTODESK, Inc Video data compression method and system which measures compressed data storage time to optimize compression rate
5574952, May 11 1994 Western Digital Technologies, INC Data storage system and method for operating a disk controller including allocating disk space for compressed data
5574953, Aug 19 1994 HEWLETT-PACKARD DEVELOPMENT COMPANY, L P Storing compressed data in non-contiguous memory
5583500, Feb 10 1993 RICOH COMPANY, LTD A CORP OF JAPAN; RICOH CORPORATION A CORP OF DELAWARE Method and apparatus for parallel encoding and decoding of data
5590306, Sep 08 1992 FUJIFILM Corporation Memory card management system for writing data with usage and recording codes made significant
5596674, Jun 24 1992 Sony Corporation; Sony United Kingdom Limited State machine apparatus and methods for encoding data in serial form and decoding using multiple tables
5604824, Sep 22 1994 FOTO-WEAR, INC Method and apparatus for compression and decompression of documents and the like using splines and spline-wavelets
5606706, Jul 09 1992 Hitachi, Ltd. Data storing system and data transfer method
5611024, Aug 28 1992 HEWLETT-PACKARD DEVELOPMENT COMPANY, L P Data compression of bit map images
5612788, Jul 30 1993 Sony Corporation; Sony United Kingdom Limited Video data compression apparatus for recording and reproducing compressed video data at their various compressed data rates
5613069, Dec 16 1994 Tony, Walker Non-blocking packet switching network with dynamic routing codes having incoming packets diverted and temporarily stored in processor inputs when network ouput is not available
5615017, Feb 21 1992 Samsung Electronics Co., Ltd. Method of and control circuit for compression recording and reproducing of multiple images
5621820, Mar 03 1994 AUTODESK, Inc Video data compression method and system which measures compressed data storage time to optimize compression rate
5623623, Sep 09 1991 Samsung Electronics Co., Ltd. Digital storage system adopting semiconductor memory device
5623701, Jun 06 1995 Western Digital Technologies, INC Data compression method and structure for a direct access storage device
5627534, Mar 23 1995 PENDRAGON NETWORKS LLC Dual stage compression of bit mapped image data using refined run length and LZ compression
5627995, Dec 14 1990 DIGITAL DATA FUNDING LLC Data compression and decompression using memory spaces of more than one size
5629732, Mar 29 1994 The Trustees of Columbia University in the City of New York Viewer controllable on-demand multimedia service
5630092, Oct 20 1994 International Business Machines System and method for transferring compressed and uncompressed data between storage systems
5635632, Apr 26 1994 Cytec Technology Corp Settling process analysis device and method
5635932, Oct 17 1994 Fujitsu Limited Lempel-ziv compression with expulsion of dictionary buffer matches
5638498, Nov 10 1992 Adobe Systems, Inc Method and apparatus for reducing storage requirements for display data
5640158, Sep 14 1994 Seiko Epson Corporation Reversible method of encoding data
5642506, Dec 14 1994 International Business Machines Corporation Method and apparatus for initializing a multiprocessor system
5649032, Nov 14 1994 Sarnoff Corporation System for automatically aligning images to form a mosaic image
5652795, Nov 14 1994 U S BANK NATIONAL ASSOCIATION Method and apparatus for an adapter card providing conditional access in a communication system
5652857, Mar 09 1995 Fujitsu Limited Disk control apparatus for recording and reproducing compression data to physical device of direct access type
5652917, Nov 13 1992 Video Associates Labs, Inc. System for transmitting and receiving combination of compressed digital information and embedded strobe bit between computer and external device through parallel printer port of computer
5654703, Jun 17 1996 Hewlett Packard Enterprise Development LP Parallel data compression and decompression
5655138, Apr 11 1995 PDACO LTD Apparatus and method for peripheral device control with integrated data compression
5666560, Aug 03 1995 Western Digital Technologies, INC Storage method and hierarchical padding structure for direct access storage device (DASD) data compression
5668737, Mar 22 1995 CSR TECHNOLOGY INC High-speed data processor and coding method
5671389, Jan 11 1996 Quantum Corporation Adaptive compression caching for tape recording
5675333, Aug 31 1994 Pendragon Wireless LLC Digital compressed sound recorder
5686916, Dec 28 1995 U S PHILIPS CORPORATION Multi-code-book variable length decoder
5694619, Sep 20 1993 Fujitsu Limited System for exclusively controlling access of a semiconductor memory module using a backup memory and compression and decompression techniques
5696927, Dec 21 1995 GLOBALFOUNDRIES Inc Memory paging system and method including compressed page mapping hierarchy
5703793, Jul 29 1994 TALON RESEARCH, LLC Video decompression
5715477, Apr 11 1995 PDACO LTD Apparatus and method for peripheral device control with integrated data compression
5717393, Feb 08 1996 Fujitsu Limited Apparatus for data compression and data decompression
5717394, Feb 10 1993 Ricoh Corporation Method and apparatus for encoding and decoding data
5719862, May 14 1996 DIODES INCORPORATED Packet-based dynamic de-skewing for network switch with local or central clock
5721958, Apr 11 1995 PDACO LTD Apparatus and method for peripheral device control with integrated data compression
5724475, May 18 1995 Timepres Corporation Compressed digital video reload and playback system
5729228, Jul 06 1995 GLOBALFOUNDRIES Inc Parallel compression and decompression using a cooperative dictionary
5748904, Sep 13 1996 XGI TECHNOLOGY, INC Method and system for segment encoded graphic data compression
5757852, Jan 24 1997 WESTERNGECO, L L C Method for compression of high resolution seismic data
5771340, Jan 14 1994 Oki Electric Industry Co., Ltd. Data compression method and print processing device utilizing the same
5778411, May 16 1995 NetApp, Inc Method for virtual to physical mapping in a mapped compressed virtual storage subsystem
5781767, Dec 03 1993 Hitachi, Ltd. Package blocking method for a storage system having a bus common to a plurality of kinds of groups of packages
5784572, Dec 29 1995 AVAGO TECHNOLOGIES GENERAL IP SINGAPORE PTE LTD Method and apparatus for compressing video and voice signals according to different standards
5787487, Nov 30 1993 Fuji Xerox Co., Ltd. Information storage system for converting data at transfer
5796864, May 12 1992 Apple Inc Method and apparatus for real-time lossless compression and decompression of image data
5799110, Nov 09 1995 Utah State University Foundation Hierarchical adaptive multistage vector quantization
5805932, Apr 22 1994 Sony Corporation System for transmitting compressed data if compression ratio is at least preset ratio and pre-compressed data if compression ratio is less than preset ratio
5808660, Sep 05 1995 Rockwell Collins, Inc Video on-demand system with a plurality of reception apparatus connected in a daisy chain connection
5809176, Oct 18 1994 Seiko Epson Corporation Image data encoder/decoder system which divides uncompresed image data into a plurality of streams and method thereof
5809337, Nov 10 1995 Intel Corporation Mass storage devices utilizing high speed serial communications
5812789, Aug 26 1996 PARTHENON UNIFIED MEMORY ARCHITECTURE LLC Video and/or audio decompression and/or compression device that shares a memory interface
5818368, Apr 18 1997 Premier Research, LLC Method and apparatus for lossless digital data compression
5818369, Mar 07 1996 Pegasus Imaging Corporation Rapid entropy coding for data compression or decompression
5818530, Jun 19 1996 Thomson Consumer Electronics, Inc MPEG compatible decoder including a dual stage data reduction network
5819215, Oct 13 1995 Hewlett Packard Enterprise Development LP Method and apparatus for wavelet based data compression having adaptive bit rate control for compression of digital audio or other sensory data
5825424, Jun 19 1996 Thomson Consumer Electronics, Inc MPEG system which decompresses and recompresses image data before storing image data in a memory and in accordance with a resolution of a display device
5825830, Aug 17 1995 Method and apparatus for the compression of audio, video or other data
5832037, Jun 23 1995 HANWHA TECHWIN CO , LTD Method of compressing and expanding data
5832126, Jul 07 1995 Oki Data Corporation Method and apparatus for compressing mixed text and image data
5836003, Aug 26 1993 AMSTR INVESTMENTS 2 K G , LLC Methods and means for image and voice compression
5838996, May 31 1994 International Business Machines Corporation; International Business Machines Corp System for determining presence of hardware decompression, selectively enabling hardware-based and software-based decompression, and conditioning the hardware when hardware decompression is available
5839100, Apr 22 1996 ALTERA CORPORATOPM Lossless and loss-limited compression of sampled data signals
5841979, May 25 1995 IRONWORKS PATENTS LLC Enhanced delivery of audio data
5847762, Dec 27 1995 Thomson Consumer Electronics, Inc MPEG system which decompresses and then recompresses MPEG video data before storing said recompressed MPEG video data into memory
5861824, Jun 20 1995 FORENSIC SCIENCE SERVICE LTD Encoding method and system, and decoding method and system
5861920, Nov 08 1996 Hughes Electronics Corporation Hierarchical low latency video compression
5864342, Aug 04 1995 Microsoft Technology Licensing, LLC Method and system for rendering graphical objects to image chunks
5867167, Aug 04 1995 Sun Microsystems, Inc. Compression of three-dimensional graphics data including quantization, delta-encoding, and variable-length encoding
5867602, Sep 21 1994 RICOH COMPANY, LTD , A CORPORATION OF JAPAN Reversible wavelet transform and embedded codestream manipulation
5870036, Feb 24 1995 International Business Machines Corporation Adaptive multiple dictionary data compression
5870087, Nov 13 1996 AVAGO TECHNOLOGIES GENERAL IP SINGAPORE PTE LTD MPEG decoder system and method having a unified memory for transport decode and system controller functions
5872530, Jan 31 1996 Hitachi, Ltd. Method of and apparatus for compressing and decompressing data and data processing apparatus and network system using the same
5883975, Sep 12 1994 Nippon Steel Corporation Compression and decompression methods on two-dimensional image data
5886655, Apr 09 1997 HEWLETT-PACKARD DEVELOPMENT COMPANY, L P Arithmetic coding context model that accelerates adaptation for small amounts of data
5889961, Jun 27 1996 Western Digital Technologies, INC Disk drive having program to be executed by a second processor stored in a first processor's ROM in a compressed form
5915079, Jun 17 1997 Hewlett-Packard Company Multi-path data processing pipeline
5917438, Jun 30 1995 JVC Kenwood Corporation Data storing and outputting apparatus
5920326, May 30 1997 HEWLETT-PACKARD DEVELOPMENT COMPANY, L P Caching and coherency control of multiple geometry accelerators in a computer graphics system
5936616, Aug 07 1996 Microsoft Technology Licensing, LLC Method and system for accessing and displaying a compressed display image in a computer system
5949355, Dec 06 1994 Cennoid Technologies, Inc. Method and apparatus for adaptive data compression
5955976, Dec 02 1997 Hughes Electronics Corporation Data compression for use with a communications channel
5960465, Feb 27 1997 Oracle International Corporation Apparatus and method for directly accessing compressed data utilizing a compressed memory address translation unit and compression descriptor table
5964842, Jan 31 1997 Network Computing Devices, Inc.; NETWORK COMPUTING DEVICES, INC Method and apparatus for scaling data compression based on system capacity
5968149, Jan 07 1998 International Business Machines Corporation Tandem operation of input/output data compression modules
5973630, Dec 02 1997 Hughes Electronics Corporation Data compression for use with a communications channel
5974235, Oct 31 1996 SENSORMATIC ELECTRONICS, LLC Apparatus having flexible capabilities for analysis of video information
5974471, Jul 19 1996 GLOBALFOUNDRIES Inc Computer system having distributed compression and decompression logic for compressed data movement
5978483, Apr 07 1997 Inkel Corporation Securely encrypted remote keyless entry system
5982723, Sep 30 1996 DISK AUTHORING TECHNOLOGIES, LLC Data recording and reproducing method for multi-layered optical disk system
5991515, Nov 10 1992 Adobe Systems Incorporated Method and apparatus for compressing and decompressing data prior to display
5996033, Sep 04 1997 Data compression device comprising input connector for connecting to game player system, output connector for connecting to memory card, and virtual memory page switch
6000009, May 06 1997 Western Digital Technologies, INC Method and apparatus for allocation of disk memory space for compressed data records
6002411, Nov 16 1994 Intellectual Ventures I LLC Integrated video and memory controller with data processing and graphical processing capabilities
6003115, Jul 29 1997 POWER MANAGEMENT ENTERPRISES, LLC Method and apparatus for predictive loading of a cache
6008743, Nov 19 1997 UNILOC 2017 LLC Method and apparatus for switching between data compression modes
6011901, May 18 1995 Timepres Corporation Compressed digital video record and playback system
6014694, Jun 26 1997 Citrix Systems, Inc System for adaptive video/audio transport over a network
6026217, Jun 21 1996 HEWLETT-PACKARD DEVELOPMENT COMPANY, L P Method and apparatus for eliminating the transpose buffer during a decomposed forward or inverse 2-dimensional discrete cosine transform through operand decomposition storage and retrieval
6028725, Jun 30 1997 EMC IP HOLDING COMPANY LLC Method and apparatus for increasing disc drive performance
6031939, Mar 17 1997 Alcatel Method of optimizing the compression of image data, with automatic selection of compression conditions
6032148, Sep 15 1997 Hewlett Packard Enterprise Development LP Multilevel storage system with hybrid data compression
6061398, Mar 11 1996 Fujitsu Limited Method of and apparatus for compressing and restoring data
6073232, Feb 25 1997 International Business Machines Corporation Method for minimizing a computer's initial program load time after a system reset or a power-on using non-volatile storage
6075470, Feb 26 1998 BlackBerry Limited Block-wise adaptive statistical data compressor
6091777, Sep 18 1997 SYS TECHNOLOGIES Continuously adaptive digital video compression system and method for a web streamer
6094634, Mar 26 1997 Fujitsu Limited Data compressing apparatus, data decompressing apparatus, data compressing method, data decompressing method, and program recording medium
6097520, Jun 30 1997 Microsoft Technology Licensing, LLC Remote control receiver and method of operation
6104389, Oct 31 1997 JVC Kenwood Corporation Broadcast receiving method and broadcast receiving apparatus therefor
6105130, Dec 23 1997 PMC-SIERRA, INC Method for selectively booting from a desired peripheral device
6128412, Sep 02 1996 Fujitsu Limited Statistical data compression/decompression method
6141053, Jan 03 1997 TERADATA US, INC Method of optimizing bandwidth for transmitting compressed video data streams
6145069, Jan 29 1999 Intellectual Ventures I LLC Parallel decompression and compression system and method for improving storage density and access speed for non-volatile memory and embedded memory devices
6169241, Mar 03 1997 Yamaha Corporation Sound source with free compression and expansion of voice independently of pitch
6172936, May 28 1998 SOCIONEXT INC Memory circuit
6173381, Nov 16 1994 Intellectual Ventures I LLC Memory controller including embedded data compression and decompression engines
6182125, Oct 13 1998 Hewlett Packard Enterprise Development LP Methods for determining sendable information content based on a determined network latency
6192082, Nov 13 1998 HEWLETT-PACKARD DEVELOPMENT COMPANY, L P Digital television data format conversion with automatic parity detection
6195024, Dec 11 1998 Realtime Data LLC Content independent data compression method and system
6195465, Sep 20 1994 RICOH COMPANY, LTD , A CORP OF JAPAN Method and apparatus for compression using reversible wavelet transforms and an embedded codestream
6222886, Jun 24 1996 Kabushiki Kaisha Toshiba Compression based reduced memory video decoder
6225922, Mar 16 1998 HEWLETT-PACKARD DEVELOPMENT COMPANY, L P System and method for compressing data using adaptive field encoding
6226667, May 26 1998 International Business Machines Corporation Method and apparatus for preloading data in a distributed data processing system
6226740, Dec 19 1997 HTC Corporation Information processing apparatus and method that uses first and second power supplies for reducing booting time
6253264, Mar 07 1997 Viasat, Inc Coding network grouping data of same data type into blocks using file data structure and selecting compression for individual block base on block data type
6272178, Apr 18 1996 NOKIA SOLUTIONS AND NETWORKS OY Video data encoder and decoder
6272627, Oct 30 1998 ATI Technologies ULC Method and apparatus for booting up a computing system with enhanced graphics
6272628, Dec 14 1998 Lenovo PC International Boot code verification and recovery
6282641, Nov 18 1998 KINGLITE HOLDINGS INC System for reconfiguring a boot device by swapping the logical device number of a user selected boot drive to a currently configured boot drive
6308311, May 14 1999 XILINX, Inc. Method for reconfiguring a field programmable gate array from a host
6309424, Dec 11 1998 Realtime Data LLC Content independent data compression method and system
6317714, Feb 04 1997 MUSICQUBED INNOVATIONS, LLC Controller and associated mechanical characters operable for continuously performing received control data while engaging in bidirectional communications over a single communications channel
6330622, Oct 23 1998 Intel Corporation Direct processor access via an external multi-purpose interface
6345307, Apr 30 1999 Google Technology Holdings LLC Method and apparatus for compressing hypertext transfer protocol (HTTP) messages
6392567, Mar 31 2000 Fijitsu Limited Apparatus for repeatedly compressing a data string and a method thereof
6404931, Dec 14 1998 Microsoft Technology Licensing, LLC Code book construction for variable to variable length entropy encoding
6421387, May 15 1998 North Carolina State University Methods and systems for forward error correction based loss recovery for interactive video transmission
6434168, Jun 07 1996 Nokia Siemens Networks Oy Data compression on a data connection
6434695, Dec 23 1998 Apple Inc Computer operating system using compressed ROM image in RAM
6442659, Feb 17 1998 EMC IP HOLDING COMPANY LLC Raid-type storage system and technique
6449682, Jun 18 1999 PHOENIX TECHNOLOGIES LTD System and method for inserting one or more files onto mass storage
6452602, Dec 13 1999 ATI Technologies ULC Method and apparatus for storing compressed data
6463509, Jan 26 1999 Rovi Technologies Corporation Preloading data in a cache memory according to user-specified preload criteria
6487640, Jan 19 1999 International Business Machines Corporation Memory access request reordering to reduce memory access latency
6489902, Dec 02 1997 Hughes Electronics Corporation Data compression for use with a communications channel
6513113, Jun 19 1998 Ricoh Company, LTD Electronic instrument adapted to be selectively booted either from externally-connectable storage unit or from internal nonvolatile rewritable memory
6529633, Sep 16 1998 Texas Instruments Incorporated Parallel difference coding method for lossless compression and real time decompression
6532121, Oct 25 1999 Hewlett Packard Enterprise Development LP Compression algorithm with embedded meta-data for partial record operation augmented with expansion joints
6539456, Oct 13 1999 Intel Corporation Hardware acceleration of boot-up utilizing a non-volatile disk cache
6542644, Sep 02 1996 Fujitsu Limited Statistical data compression/decompression method
6577254, Nov 14 2001 HEWLETT-PACKARD DEVELOPMENT COMPANY, L P Data compression/decompression system
6590609, Feb 21 1997 MAXELL, LTD Image signal recording system
6601104, Mar 11 1999 Realtime Data LLC System and methods for accelerated data storage and retrieval
6604040, Dec 14 2000 Sumitomo Rubber Industries, Limited Apparatus and method for identifying tires and apparatus and method for evaluating road surface conditions
6604158, Mar 11 1999 Realtime Data, LLC System and methods for accelerated data storage and retrieval
6606040, Feb 13 2001 GOOGLE LLC Method and apparatus for adaptive data compression
6606413, Jun 01 1998 Carl Zeiss Microscopy GmbH Compression packaged image transmission for telemicroscopy
6609223, Apr 06 1999 KENCAST, INC METHOD FOR PACKET-LEVEL FEC ENCODING, IN WHICH ON A SOURCE PACKET-BY-SOURCE PACKET BASIS, THE ERROR CORRECTION CONTRIBUTIONS OF A SOURCE PACKET TO A PLURALITY OF WILDCARD PACKETS ARE COMPUTED, AND THE SOURCE PACKET IS TRANSMITTED THEREAFTER
6618728, Jan 31 1996 Hewlett Packard Enterprise Development LP Multi-process compression
6624761, Dec 11 1998 Realtime Data, LLC Content independent data compression method and system
6661839, Mar 24 1998 Advantest Corporation Method and device for compressing and expanding data pattern
6661845, Jan 14 1999 Vianix Delaware, LLC Data compression system and method
6704840,
6711709, Jun 24 1998 Unisys Corporation Integrated block checking system for rapid file transfer of compressed data
6717534, Jan 18 2002 Fuji Xerox Co., Ltd. Data encoding device and data decoding device
6731814, May 01 2000 Xerox Corporation Method for compressing digital documents with control of image quality and compression rate
6745282, Jan 13 1995 Fujitsu Limited Compressed data managing apparatus and method therefor to manage compressed data of a disk storage
6748457, Feb 03 2000 Realtime Data, LLC Data storewidth accelerator
6756922, May 21 2001 International Business Machines Corporation Method and system for compression of a set of mostly similar strings allowing fast retrieval
6810434, Dec 29 1997 KAWASAKI MICROELECTRONICS, INC Multimedia interface having a processor and reconfigurable logic
6885316, Feb 05 2001 System and method for keyboard independent touch typing
6885319, Jan 29 1999 Intellectual Ventures I LLC System and method for generating optimally compressed data from a plurality of data compression/decompression engines implementing different data compression algorithms
6909383, Oct 05 2002 Qualcomm Incorporated Systematic encoding and decoding of chain reaction codes
6944740, Mar 27 2002 International Business Machines Corporation Method for performing compressed I/O with memory expansion technology
7102544, May 31 2005 TAHOE RESEARCH, LTD Method and system for improving memory interface data integrity in PLDs
7130913, Mar 11 1999 Realtime Data LLC System and methods for accelerated data storage and retrieval
7161506, Dec 11 1998 Realtime Data LLC Systems and methods for data compression such as content dependent data compression
7190284, Nov 16 1994 Intellectual Ventures I LLC Selective lossless, lossy, or no compression of data based on address range, data type, and/or requesting agent
20010031092,
20010032128,
20020037035,
20020101367,
20020104891,
20020126755,
20030030575,
20030034905,
20030084238,
20030142874,
DE4127518,
EP164677,
EP185098,
EP283798,
EP405572,
EP493130,
EP587437,
EP595406,
EP718751,
GB2162025,
JP11149376,
JP6051989,
JP9188009,
WO9414273,
WO9429852,
WO9502873,
WO9748212,
/
Executed onAssignorAssigneeConveyanceFrameReelDoc
Apr 08 2006Realtime Data LLC(assignment on the face of the patent)
Date Maintenance Fee Events
Oct 20 2011M1551: Payment of Maintenance Fee, 4th Year, Large Entity.
Oct 24 2011STOL: Pat Hldr no Longer Claims Small Ent Stat
Nov 04 2015M1552: Payment of Maintenance Fee, 8th Year, Large Entity.
Jan 06 2020REM: Maintenance Fee Reminder Mailed.
Jun 22 2020EXP: Patent Expired for Failure to Pay Maintenance Fees.


Date Maintenance Schedule
May 20 20114 years fee payment window open
Nov 20 20116 months grace period start (w surcharge)
May 20 2012patent expiry (for year 4)
May 20 20142 years to revive unintentionally abandoned end. (for year 4)
May 20 20158 years fee payment window open
Nov 20 20156 months grace period start (w surcharge)
May 20 2016patent expiry (for year 8)
May 20 20182 years to revive unintentionally abandoned end. (for year 8)
May 20 201912 years fee payment window open
Nov 20 20196 months grace period start (w surcharge)
May 20 2020patent expiry (for year 12)
May 20 20222 years to revive unintentionally abandoned end. (for year 12)